Caitlin Wilson
Reporting from Washington, DC

We're wrapping up our live coverage of a busy day in US politics. Thank you for joining us.

You can read more about today's top stories below:

This Nato summit could save or sink Biden's candidacy

Democrats look to Kamala Harris - but could she beat Trump?

Congressional Democrats hold critical meetings over Biden candidacy

Trump vice-president pick: Who will be the Republican's running mate?

This page has been edited by Brandon Livesay, Caitlin Wilson, Phil McCausland and Graeme Baker. Our writers have been Rachel Looker, Max Matza, Kayla Epstein and Mike Wendling.

It’s been an eventful day - here are some of the political highlights we’ve been covering in Washington and elsewhere.

• Democrats held meetings today and further discussions about President Joe Biden’s candidacy
• Another member of the Democratic bloc in the House of Representatives, Mikie Sherrill, said that Biden should end his campaign
• But the party leadership and many high-profile lawmakers continue to support the president
• Meanwhile the White House news briefing grew heated when reporters pressed for more information about Biden's health and fitness
• Biden himself delivered a speech at the opening of the Nato summit and promised "dozens of additional tactical air defence systems" for Ukraine
• Speaking at a campaign rally, former President Donald Trump made light of Democratic Party debates and contrasted their "full-scale breakdown" with what he said was Republican unity
• Talking to a friendly crowd in Florida, he also challenged Biden to another debate without moderators

Image source, Reuters

The former president brings up Nato to tell another story he’s fond of – that Nato allies were failing to pay their bills until he drove a hard bargain.

“I said what the hell are you doing, nobody’s paying,” Donald Trump says.

The truth is less dramatic. Few Nato allies fall behind in contributing to the alliance itself, but it seems that Trump is referring to guidelines that allies should spend 2% of their gross domestic product on defence. Less than half of members meet that mark, which has no legal force.

Under Trump’s telling, though, he told the Atlantic allies “No, I will not protect you from Russia” if they refused to stump up more cash, and “hundreds of billions of dollars” started pouring in.

In the middle of a rant about the alleged corruption of the Biden family, Donald Trump claims that Hunter Biden – the president’s son who has just been convicted of a gun charge – is the real power behind the presidency, possibly referring to recent reports that Hunter has joined in on some meetings with his father.

“He’s running our government,” Trump shouts. “Hunter is in the White House running the government right now.

“No wonder Joe doesn’t want to give up the job.”

Trump’s own advisors in the White House included his daughter Ivanka Trump and her husband, Jared Kushner.

Tom Bateman
BBC News

Image source, Reuters

Speaking at the opening of the Nato summit earlier tonight, Joe Biden had two audiences to convince. One was in the hall full of political and military leaders from all over the world, the other - millions of ordinary Americans for whom the most of this speech they’ll likely see will be a few soundbites on social media or TV tonight.

The tougher crowd is the latter, who have absorbed ten consecutive days of lead story headlines questioning Biden’s electoral future due to his age after his disastrous debate performance against Donald Trump.

He passed that test - one of many he’s subjected himself to at rallies and interviews for the last week and a half as part of the ongoing damage control. This was an energised speech, pretty much flawless apart from a couple of minor fluffs or stutters. But it was 13 minutes read from a teleprompter on safe ground.

On the substance - the issue of NATO’s future amid war in Europe - there was a pledge for a "historic donation" of more air defence systems for Ukraine, which includes a new US Patriot system.

Significantly, he spoke of both Democrats and Republicans in the room - an attempt to talk up bipartisan support for Nato - and invoked the history of Ronald Reagan facing off the Soviets – Reagan is a favoured reference for Democrats trying to expose Republican divisions and what they see as the maverick modern isolationism of Trump. The subtext is: Reagan would turn in his grave at Trump’s Nato-sceptic stance.

In a sense the reactions of these two audiences - in the room and at home - are linked: Biden needed to show personal resolve against Russia and political unity at home; both depend fundamentally on his performance.

Image source, Reuters

The former president returns to his usual themes - border security, false allegations that the 2020 election was stolen from him, and the "socialist" and "communist" Democrats.

"Our country's going down the tubes," he says, alleging a plot by leading Democrats to hide information about Joe Biden's health.

He promises a landslide victory and repeats another common theme, that there is an "invasion" of people coming through the US southern border.

Donald Trump begins his rally speech by touting what he calls the unity of the Republican party and his appeal to minorities and young voters.

"Meanwhile the radical left Democrat party is divided in chaos and having a full scale breakdown, all because they can't decide which of their candidates is more unfit to be president," he said.

Trump continues by offering Biden - perhaps not entirely seriously - a chance at another debate this week, only without moderators.

"It's a shame the way they're treating him, but don't feel sorry for him, he's a bad guy, he weaponised government," Trump continues, before issuing another challenge to Biden, to a golf match.

Image source, Reuters

A parade of golf carts pulled up behind the stage at the Trump rally in Florida.

Presumably one of the carts carried the former president, as he is now taking the stage.

As we wait for Donald Trump to take the stage, here are some photos from the crowd in Florida.

Image source, Reuters

Image source, Reuters

Image source, Getty Images

Image source, Getty Images

Cecilia Barría
BBC Mundo, Florida

As the Democrats continue to debate their future, a crowd of Republican supporters - complete with red flags and MAGA hats - are gathering for a rally at Donald Trump's Golf Club in Doral, Florida a suburb of Miami.

Trump himself is scheduled to speak in a bit.

On this hot summer day - 92 degrees F (33 Celsius) - former President Trump will rally voters in his home state at his flagship golf resort in a celebratory mood as Democrats face tough calls over President Joe Biden’s re-election chances.

Trump supporters here tell me they are excited to participate as the Republican is expected to announce his vice-presidential running mate in the coming days.

Though Democrats are grappling with questions over 81-year-old Biden's age, Trump supporters here tell me they're not worried about their candidate's 78 years.

"Trump is bright, I don’t see a problem at all with his age”, says Eduardo Gallardo.

“He is brilliant,” his wife Patricia Gallardo adds.

“He is like a bull on steroids," says another supporter called, Jonathan, sporting a big smile

Domestic politics have been hanging heavily over this Nato meeting, and the argument over whether President Biden should stay in the race shows no sign of stopping soon.

Today New Jersey Congresswoman Mikie Sherrill became the latest Democratic lawmaker to call for Biden to quit the race. In a statement she lauded his presidency and long career, but said “the stakes are too high – and the threat is too real – to stay silent.

“And because I know President Biden cares deeply about the future of our country, I am asking that he declare that he won’t run for re-election and will help lead us through a process toward a new nominee.”

A handful of Democratic members of the House of Representatives have now called for Biden to halt his campaign.

Although no senators have joined them, CNN reported that three prominent Democratic senators - Michael Bennet of Colorado, Sherrod Brown of Ohio and Jon Tester of Montana – said they don’t believe the president can win re-election against Donald Trump.

Others have been more bullish about his prospects however. Hank Johnson of Georgia, a member of the Congressional Black Caucus, told the BBC that Democrats need to “break the circular firing squad”.

Johnson told Radio 4's The World Tonight that he was still backing Biden and that if his party can “get in formation”, they can retain the White House in November.

We are getting more details about that pledge for additional aid to Ukraine that Joe Biden announced during his speech opening Nato.

US officials say the package will include air defences including Patriot missiles and components. The five countries – also including Germany, Netherlands, Romania and Italy – say another announcement about air defence systems will come later this year.

In coming months, US officials say, the allies will provide Ukraine with dozens of other tactical air defence systems.

Other countries will be involved in that round – including the UK, Canada, Norway and Spain.

Just yesterday Ukranian officials were asking for additional defences, after Russia launched a missile barrage. A children's hospital was hit, 36 were killed and 140 were injured.

"Our defence capabilities are still insufficient,” said Ukraine's Defence Minister Rustem Umerov. “We need more air defence systems.”

It now appears he’ll be getting at least some of what he’s asking for from Western allies.

Biden's Nato speech: part history lesson, part call to armspublished at 23:36 9 July

23:36 9 July

Anthony Zurcher
BBC North America correspondent

Joe Biden’s address at the Nato summit this evening was part history lesson, part call to arms.

After recounting the alliance’s successes over the past 75 years, he said its work was not done.

“This moment in history calls for our collective strength,” he said.

Even though this was a celebratory event – marking a “milestone year” – Biden’s delivery was stern, befitting a man in the midst of some of the most formidable challenges of his political career.

The president’s speech probably gave little material for his critics to use against him and highlighted the work he has done to strengthen and expand Nato, which is one of the most notable accomplishments of his near four years in office.

But from here on out, Biden’s re-election campaign is like a racetrack filled with hurdles. He can only get to the finish line if he clears all the obstacles in front of him. Tonight was just the first of many – and far from the most daunting.

Image source, Reuters

Joe Biden's speech to Nato leaders tonight was forceful and clearly delivered - in obvious contrast to his often halting and disjointed debate performance last week that has cast uncertainty on his political future.

Reading from a teleprompter in the Washington DC auditorium, Biden's words were strong and steady as he spoke about the need for the global allegiance to continue 75 years after it was first founded.

Since Biden's debate last month against his presidential opponent Donald Trump in Atlanta, where he stumbled over words and seemed flustered, polls have shown him losing ground to his Republican rival.

Political pundits - and global leaders - are watching Biden's behaviour during this Nato summit for any signs that he is reconsidering his re-election campaign. Biden has insisted that he will not drop out.

Biden has finished speaking and has left the stage along with Nato Secretary General Jens Stoltenberg.

A military choir is now singing "Let there be peace on Earth".

Stick with us as we continue to bring you all the latest news and analysis from this busy day in Washington.

And now the biggest news from Biden's speech.

After announcing that "Ukraine can and will stop Putin", the president shared some welcome news for Ukrainians.

He said that the US and four other countries - Germany, Netherlands, Romania and Italy - would provide Ukraine with "dozens of additional tactical air defence systems" within months.

This comes a day after a children's hospital in Kyiv was hit by missiles, leaving several people dead and hundreds injured.

Quoting former president Ronald Reagan, Biden says: "If you are threatened, we are threatened. If you are not at peace we cannot be at peace."

He then calls Secretary General Stoltenberg, who jogged to the stage to shake Biden's hand.

"So much of the progress we made in the alliance is thanks to the secretary. He's a man of integrity and intellectual rigour," he says, adding that Stoltenberg "works across the political spectrum" in support of Nato.

He adds that he is awarding Stoltenberg the Presidential Medal of Freedom - the highest civilian honour the president can bestow.

Image source, Nato

The president - perhaps hoping to contrast his attitude with Donald Trump's stance - points out that there are both Republicans and Democrats in the crowd showing support for the military alliance.

"An overwhelming bipartisan majority of Americans understand that Nato makes us all safer," he says.

“The American people understand what would happen if there was no Nato,” he says, painting a picture of war and economic catastrophe.

Image source, Getty Images

President Joe Biden goes on to says that 23 nations are now spending the mandatory 2% of GDP on defence spending, and that the alliance is committed to preventing autocrats from taking power.

"Remember Nato's character is fundamentally democratic," he says, adding: "Always will be".

"This moment in history calls for our collective strength," he says.

"Putin wants nothing less than Ukraine's total subjugation, to end Ukraine's democracy, and to destroy Ukraine's culture, and to wipe Ukraine off the map," he continues.

"And you know Putin won't stop in Ukraine. Make no mistake: Ukraine can and will stop Putin."