Republicans were quick to praise the president's leadership and back up his call for US allies to do more.

Senator Rand Paul - who was critical of the Soleimani strike - said he was "pleased" at the president's decision to pull back.

His fellow Republican senator Richard Shelby was also supportive, and Trump ally Senator Lindsey Graham called on America to "support President Trump’s efforts to resolve the threat from Iran peacefully".

Across the aisle, Democrat Hank Johnson also offered some praise for the address - albeit with the quip: "I'm glad the adults are now being heard!"

Other Democrats had harsher words - California Congressman Jimmy Gomez criticised the president for lashing out, yet again, at his predecessor, Barack Obama.

Top Democrat Chuck Schumer did not directly reference Trump's address, but said: "Americans do not want a war with Iran."

Iranian news agency Fars quotes the chief spokesman of the Iranian Armed Forces, Brig Gen Abolfazl Shekarchi, as blaming US “psychological warfare” for what he calls “rumours” that the Ukrainian passenger plane which crashed in Tehran was hit by something.

Gen Shekarchi says the rumours are “completely false” and “ridiculous”.

Iraq's foreign ministry has summoned the Iranian ambassador in Baghdad over the missile attacks.

In a statement, the ministry said Iraq rejected "the attacks on camps housing Iraqi and non-Iraqi forces, and we deem them to be a violation of our sovereignty".

"Iraq is an independent state and... its internal security is its priority. We will not allow it to become a battlefield," the statement added.

Donald Trump has spoken about the Iranian missile strikes on two bases in Iraq which are hosting US forces.

Here are five key things he said:

• No Americans were harmed in the attack and there was only "minimal damage" to the targeted sites
• He said Iran "appears to be standing down" which was a "very good thing for the world"
• The US will impose extra "punishing" sanctions on Iran
• He promised Iran will never get nuclear weapons
• He called on European powers, Russia and China to abandon the 2015 Iran nuclear deal

Mr Trump said the US assassination of Qasem Soleimani sent a message to terrorists: "If you value your own life, you will not threaten the lives of our people."

President Trump ended his speech by saying the US was ready to "embrace peace with all who seek it".

"God bless America", he said, before walking off the stage.

President Trump calls on Europe and the other parties to the 2015 Iran nuclear accord - signed by the Obama administration - to pull away from the deal, adding that world powers should negotiate a new deal.

He added that he would ask Nato to "become much more involved" in the Middle East.

President Trump says the US will impose "'additional punishing sanctions" on Iran, which has already faced hardship from US sanctions under the Trump administration.

Mr Trump says Iran has been the "leading supporter of terrorism" and that the country had "threatened the civilized world".

He called Iranian general Qasem Soleimani "the world's top terrorist", and said Soleimani's hands were "drenched in blood".

Mr Trump says US forces are "prepared for anything," but for now, "Iran appears to be standing down".

"Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world," he said.

"As long as I'm president of the United States Iran will never be allowed to have a nuclear weapon", says Mr Trump, introducing his statement.

The president, flanked by top officials, has begun his address in Washington.

US Senate Majority Leader Mitch McConnell said he was grateful for President Trump's "patience and prudence" in determining how to respond to Iran's missile attack.

Mr McConnell said he spoke to Mr Trump after the Iran strikes, and praised the president for not immediately reacting.

He said he believed the president wanted to "avoid conflict" but was "rightly prepared to protect American lives and interests".

"I hope Iran’s leaders do not miscalculate by questioning our collective will in launching further attacks," he said.

The identities of the 176 passengers on board the Ukraine International Airlines flight which crashed in Iran are emerging.

Officials said there was no chance of finding survivors.

The plane crashed moments after takeoff from the capital, Tehran, hours after rocket strikes by the Iranians against targets in Iraq. There was no evidence that the two incidents were linked.

Ukraine International Airlines named the nine crew, including three pilots and six flight attendants. Among those who died was Valeriia Ovcharuk, a 28-year-old who posted pictures on social media of several of the destinations she had visited with the airline.

A British man has also been named.

BP engineer Sam Zokaei, who had been on holiday, was among three people from the UK on board.

BP said it was "shocked and deeply saddened" by the loss of its friend and colleague.

Image source, FACEBOOK

The majority of passengers on board were from Iran and Canada, some of whom are thought to have held dual-nationality.

Ten Swedes, four Afghans, and three Germans also died, the Ukrainian Foreign Minister Vadym Prystaiko said.

Fifteen of the dead were children. Ukrainian officials said that 169 people had bought tickets for the flight but two had not boarded the plane.

President Trump is expected to make a statement shortly on the Iranian missile attacks in Iraq. Earlier, he tweeted "all is well!" and "so far, so good' after a briefing with senior officials.

BBC Monitoring
The world through its media

Iran's Tasnim news agency, which is close to the Islamic Revolutionary Guards Corps (IRGC), said Fateh-313 and Qiam missiles were used in the overnight attack on the Al Asad air base.

The domestically-made ballistic missiles have a range of 500 km (310 miles) and 800 km, respectively, it said.

Tasnim added that US forces failed to intercept the missiles fired from Iran because they were equipped with cluster warheads, which can disturb the normal performance of anti-missile rockets.

The agency said this allowed the missiles to cause "tens of explosions" in the base.

Former Iranian Defence Minister Hossein Dehqan said in 2013 that the country had developed a "new generation of missiles" equipped with cluster warheads.

A cluster warhead missile contains several warheads, each capable of being aimed at a different target.

Image source, AFP

The presidents of Turkey and Russia issued a joint statement calling for the US and Iran to exercise restraint.

Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin said an exchange of attacks would lead to a "new cycle of instability".

"We express our commitment to ease the current tension in the region and call on all sides to act with restraint and discretion and prioritise diplomacy," they said.

The leaders issued the statement following a meeting in Istanbul, where they inaugurated the TurkStream pipeline, which will carry Russian gas to southern Europe via Turkey.

Iraq’s President, Barham Saleh, has denounced the Iranian missile strikes on two Iraqi bases hosting US forces.

“[We] renew our rejection of the repeated violation of state sovereignty and the transformation of Iraq into a battlefield for warning sides,” his office said in a statement.

Image source, Anadolu Agency

If you are just joining us, this is what we know so far about Iran's missile attack:

• Two airbases housing US and other coalition troops in Iraq were hit by ballistic missiles from Iran
• Iran said it launched the attack in retaliation for the death of powerful military commander, Qasem Soleimani, who was killed last week in a drone strike ordered by US President Donald Trump
• Iran's Supreme Leader Ayatollah Khamenei said the attack was a "slap in the face" for the US and called for an end to the US presence in the Middle East

• It is unclear if there have been any casualties

• US President Donald Trump - who earlier tweeted that "all is well" - is expected to make a statement at 16:00 GMT

• Hours after the missile attack, a Ukrainian Boeing-737 carrying 176 people, the majority of whom were Iranians and Canadians, crashed in Iran with no survivors
• Iran blamed technical problems, while Ukraine's Tehran embassy initially blamed engine failure but later removed the statement and said any comment on the cause of the crash prior to an inquiry was not official
• There is no evidence that the missile attack and plane crash are linked

Tom Burridge
Transport correspondent, BBC News

A Ukrainian Boeing-737 carrying 176 people has crashed in Iran and officials say there is no chance of finding survivors.

Flight data from the Ukrainian Airlines Boeing 737-800 is openly available online. It shows that the plane climbed normally after taking-off from Tehran, before it crashed, carrying 176 people.

It reached nearly 8,000ft (2,400m) before the aircraft's data suddenly disappears.

This is unusual and would suggest some type of catastrophic incident on board the plane. We have no evidence at this stage to tell us what caused the incident.

According to a former air crash investigator, any suggestion of engine failure feels premature. This possibility can't be ruled out at this early stage but an airliner such as the Boeing 737-800 is designed to keep flying if there is an engine failure.

Plus, if there was a failure then we would normally expect the flight data to show the plane's climb becoming less steep.