A UN official has told the meeting of the body's Security Council that tensions in and around Ukraine are higher than at any point since 2014.

"Speculation and accusations around a potential military conflict are rife," cautions UN political affairs chief Rosemary DiCarlo.

But she adds that "whatever one believes about the prospect of such a confrontation, the reality is that the current situation is extremely dangerous."

The UN, she says, is fully engaged with all actors in the conflict and believes that there is no alternative to diplomacy.

We're hearing from US Secretary of State Anthony Blinken.

He's speaking at the UN Security Council and says the US is convinced a Russian attack on Ukraine will begin with a manufactured pretext, which could come in several forms.

He says the US is unsure "what form" such a pretext could take, but possibilities include a fabricated terrorist bombing in Russia, the discovery of a mass grave, or a fake - or real - chemical weapons attack.

In the aftermath of such an incident, Blinken says Russia's government will likely "theatrically convene" an emergency meeting. After that, Russian missiles and bombs would begin striking Ukrainian targets, as well as jamming of communications and cyber attacks.

"After that, Russian tanks and soldiers will advance on key targets that have already been identified," he adds.

However, Blinken says that Russia can still choose "a different path" while "there's still time".

Russia has repeatedly denied similar US accusations and has said it is withdrawing forces from the region.

Gordon Corera
Security correspondent, BBC News

When it first emerged Russian "trolls" were actively spreading misinformation online in 2014, a group of volunteers decided to take them on.

The "elves" - as they call themselves - first emerged in Lithuania before spreading across Central and Eastern Europe. There are now up to 4,000 anonymous activists involved. One elf told the BBC they are on high alert over Ukraine.

Ukraine crisis: Is Russia waging an information war?

Baltic elves say in the past 24 hours they have been working with Ukrainians to help get out the truth. This includes stopping false stories taking hold in the wake of reports we've covered earlier today of shelling at a kindergarten in Ukraine's Luhansk region. One key narrative they are seeing accuses the Ukrainian government of committing genocide against Russians in the eastern part of the country.

Czech elves point to a series of false narratives pushed within their own country too, including the claim Ukraine is "fascist" and torturing people as part of a genocide. Another is that it is the West, and not Russia, that is provoking war in Ukraine with Nato troops already present near the Russian border.

Image source, Ukrainian Chief of General Staff / Handout

As we've been reporting, Western leaders have been sharing their fears that Russia could be preparing to stage a false-flag attack to justify invading its neighbour.

This is an allegation we've heard before. Earlier this year the US claimed Russia was planning to fabricate a pretext to invade.

While Washington offered plenty of intriguing detail - alleging that Moscow was planning to release a graphic video showing the attack - it failed to provide any evidence.

The reason we're hearing more of these allegations today is because of reports of shelling in the Donbas region of eastern Ukraine, where Russia-backed rebels have been fighting Ukrainian troops since 2014.

Detail from the ground has been difficult to come by so far, and both sides have given conflicting accounts of what's happening. A kindergarten was hit by shell this morning in an area controlled by Ukraine in what the government called a "big provocation" by Russian-backed rebels.

This apparent upsurge in violence has prompted the US, UK and Nato to all warn Russia could be laying the ground to invade imminently. UK Prime Minister Boris Johnson even said outright that the reported shelling was "designed to create a pretext".

But it's worth remembering tensions are high and - in terms of evidence to support the pretext allegations - we have so far seen very little.

The allegations, however, are continuing to pile up. This afternoon, US President Biden has echoed the claims from other Western leaders. "[Russia is looking] to have an excuse to go in," he told reporters at the White House.

BBC Monitoring
The world through its media

Moscow has said the US did not give a constructive answer to its proposals for "security guarantees", and may take "military-technical measures" in response, the written Russian response to the US says, according to reports from the Interfax news agency.

"We are stating that the American side did not give a constructive response to the basic elements of the draft treaty with the United States prepared by the Russian side on security guarantees," Moscow said in the document, Interfax reports.

"In the absence of readiness on the American side to agree on firm, legally binding guarantees to ensure our security from the United States and its allies, Russia will be forced to respond, including by implementing measures of a military-technical nature," the document says.

Image source, EPA

We've heard from US President Joe Biden, he has told reporters there is "every indication" that Russia will launch an attack on Ukraine "in the next several days".

Speaking on the White House lawn, Biden said that the threat of a Russian invasion is "very high".

As evidence, he pointed to the US government's belief that additional Russian forces have been deployed near Ukraine's border, and that the US government believes it is "engaged in a false-flag operation to have an excuse to go in".

However, Biden added that he believes a diplomatic solution is still possible. He said he has no immediate plans to call Russian President Vladimir Putin.

Russia has repeatedly denied planning to invade. Earlier today Foreign Minister Sergei Lavrov said suggestions an invasion was imminent were "disinformation".

There's time for one more question from the media at the press conference in Kyiv.

The UK and Ukrainian officials are asked if Russia is trying to create a pretext for its invasion of Ukraine.

Ukraine's Foreign Minister Dmytro Kuleba says since 2014 they have seen provocations, baseless accusations and doctoring reality, always aimed at putting responsibility on Ukraine's shoulders in order to justify Russian actions and give additional pretext for escalation.

He says that's why they are working with the whole world to ensure any Russian attempt to distort reality will not be fruitful and to make sure Ukraine is ready for any scenario.

The UK's Foreign Secretary Liz Truss adds we are seeing a false-flag operation and Russia is the aggressor and we will continue to call them out.

Russia has accused the West of "hysteria" over such warnings in recent weeks.

UK Foreign Secretary Liz Truss has been taking questions from the media at the press conference in Kyiv.

She is asked if it's more likely there is going to be an imminent offensive by Russia or a prolonged stalemate.

Truss says: "There is a significant chance there could be offensive action by Russia, if not, why are there 100,000 troops on the border with Ukraine?"

But Russia can take the path of diplomacy, de-escalate and move their troops from the border, she says.

This is in the interest of European security but also Russia's interests, she adds.

Image source, Reuters

If Russia does not take the path of diplomacy, the UK is ready with its allies to impose severe economic costs, Foreign Secretary Liz Truss says.

The US have been clear that Nord Stream 2 would not go ahead, she says.

Russia risks a prolonged and drawn out war with a terrible toll which would be borne by the Russian people.

"Russia would confirm its status as an international pariah," she says, while urging the Kremlin to de-escalate and choose diplomacy.

Ending her statement to the press conference she says: "Together we can turn the tide on Russian aggression and we can build a more secure future for all of us, right across Europe."

The UK will increase its funding for projects to supply Ukraine with defensive weapons and army training from £80m to £100m, Foreign Secretary Liz Truss has announced.

On the tri-lateral partnership with Ukraine and Poland just announced by her Ukrainian counterpart, she says together they will intensify work on defence, security, sanctions, energy security and countering disinformation.

"Russia must think again," says Truss. "Despite their claims Russia's military build up shows no signs of slowing. There is currently no evidence that their forces are withdrawing and we need Russia to step back from the brink. They must take the path of diplomacy."

When asked about a so-called "false flag" operation that experts fear Russia might use to justify its invasion, Ukrainian FM Kuleba says "We're very much ready for any situation".

He says Ukraine has been working with the international community to "make sure" any such attempt fails.

Kuleba earlier also announced the setting up of a strategic partnership between Ukraine, the UK and Poland.

UK Foreign Secretary Liz Truss is now speaking in Ukraine's capital Kyiv where she is in talks aimed at averting a possible Russian invasion.

She tells a press conference she is there to show the UK's steadfast support for Ukraine.

Truss says she is impressed that despite Russian aggression life goes on in Ukraine and she admires the stoicism and fortitude of the Ukrainain people and their government.

She says the UK stands shoulder to shoulder with Ukraine to defend their right to decide their future.

The Ukrainian-British strategic partnership has reached "an unprecedented level", Ukrainian Foreign Minister Dmytro Kuleba says at the start of the joint news conference, alongside his UK counterpart Liz Truss, in Kyiv.

He says that "actions speak louder than words" and that London has shown its readiness to act".

"We can never say for sure what happens tomorrow, but today we do our utmost" to maintain peace, Kuleba says.

"Diplomacy is working," he adds.

The US has confirmed Russia has expelled a senior diplomat at its embassy in Moscow, calling the move an unprovoked "escalatory step".

As we've been reporting, Russia has expelled the US deputy ambassador Bart Gorman, the second-most senior official at the embassy - but Moscow has not yet said why.

The US State Department says Moscow's action was "unprovoked and we consider this an escalatory step and are considering our response".

"We call on Russia to end its baseless expulsions of US diplomats and staff and to work productively to rebuild our missions," the department says.

"Now more than ever, it is critical that our countries have the necessary diplomatic personnel in place to facilitate communication between our governments."

Jonathan Beale
BBC defence correspondent

Nato Allies and Western officials are expressing increasing concern that Russia could use alleged violations of the fragile ceasefire in Ukraine's Donbas region as a justification to mount an invasion.

Nato's Secretary General, Jens Stoltenberg, said "we are concerned Russia is looking for a pretext to invade".

Both sides have accused each other of breaking the ceasefire. But Western officials say they have seen no evidence to back up Moscow's claim that Ukraine's forces recently opened fire with artillery on pro-Russian separatist positions.

The US Defence Secretary, Lloyd Austin. said reports of shelling were troubling. He added: "We've been saying for some time that Russia might do something like this to justify a military conflict."

The UK Defence Secretary Ben Wallace warned the Kremlin "will peddle more false stories".

"I predict, if Putin has decided he's going to invade, you'll see false stories around, genocide, incursions and breaches of ceasefire" in Donbas, he said, adding the West was already seeing Russia "raising the rhetoric" around the separatist region. Wallace described it as part of Russia's playbook.

Image source, Reuters

German Chancellor Olaf Scholz has spoken briefly to the BBC after a meeting of EU leaders in Brussels.

"If there is military aggression towards Ukraine there will be consequences and we are ready to react with sanctions" on Russia, he says, adding the leaders want to use diplomacy to resolve the crisis.

He adds: "We know at the same time that there are still lots of soldiers and troops along the Ukrainian border. This is threatening and remains a threatening situation. We can’t be naive about this."

Too early to tell if Russia is pulling back troopspublished at 14:21 Greenwich Mean Time 17 February 2022

14:21 GMT 17 February 2022

Paul Adams
BBC diplomatic correspondent in Ukraine

It's going to take time to figure out what Russia's movements and intentions are. They've always said that once these various exercises are over we will see troops returning to their bases.

And you see within those exercises some movements to and fro, so I would urge people not to over analyse the images we see from one moment to the next.

There are people poring over the satellite images and intelligence in Western capitals and they will reach a conclusion about whether what we are seeing represents a genuine de-escalation.

But it's way too early to have that conversation - it will emerge but it could take a very long time.

Meanwhile there are moments of tension which could generate a full-blown crisis. We've been bringing you reports of shelling of a kindergarten. Every day when you hear about episodes like that you are wondering is this going to be the trigger for something.

While the political situation remains unresolved there's enormous potential for one of these fairly routine exchanges of gunfire to explode into something bigger or to be interpreted, deliberately or accidentally, as representing something bigger.

It has a long-term corrosive psychological effect here in Ukraine, and that may be the effect that Vladimir Putin wants it to have.

Image source, PA Media

We're expecting to hear from the UK Foreign Secretary Liz Truss in Kyiv soon.

But PM Boris Johnson has also been speaking about the situation in Ukraine and Russia.

He says: "There is still time for the Putin regime to step back.

"There is still time to avoid a catastrophe, a catastrophe for Russia, a catastrophe for Ukraine and for the world.

"If Russia were so mad as to invade, I don't think people should imagine that this would be a brief business.

"This would be a bloody and protracted conflict in which, I'm afraid, there will be many casualties and including many Russian casualties. I just hope that people in Russia can see that."

Some news just in - Russia has expelled the the deputy US ambassador at the US embassy in Moscow, according to the Russian state-run news agency RIA.

It's not immediately clear what reason Moscow has given for expelling the diplomat, Bart Gorman. The US will respond to the move, RIA reports.

Image source, EPA

US Defence Secretary Lloyd Austin claims Russia is moving troops closer to Ukraine's border and is stocking up on blood supplies.

Speaking in Brussels, Austin says the US is also seeing Russia "fly in more combat and support aircraft" and is sharpening their "readiness in the Black Sea”.

"I was a soldier myself not that long ago. I know first-hand that you don't do these sorts of things for no reason," Austin, a retired army general, says.

"And you certainly don't do them if you're getting ready to pack up and go home."