Our live coverage has ended. Scroll through the posts below to read more about the NATO summit.
Trump and Macron clash at NATO summit
By Sheena McKenzie and Meg Wagner, CNN
President Trump arrived for a NATO reception at 10 Downing Street a few minutes ago, with French President Emmanuel Macron, having apparently given the French President a ride.
He waited a few minutes and then entered with first lady Melania Trump.
Trump and Macron have had a tense day: It started when Macron described the long-time coalition as suffering from "brain death" in part due to a lack of US leadership under Trump. Trump called those comments "insulting." Later, the two held a news conference, where Macron corrected Trump about ISIS fighters.
What's happening at the reception: A choir ran through Christmas songs as guests began arriving, including Hark the Herald Angel, Walking in a Winter Wonderland and We Wish You a Merry Christmas.
Jens Stoltenberg, Secretary General of NATO, was first to arrive followed shortly after by Canadian Prime Minister Justin Trudeau, then German Chancellor Angela Merkel, who stopped to admire the choir.
The NATO leaders are attending a reception hosted by British Prime Minister Boris Johnson, and had come from a separate reception hosted by Queen Elizabeth at Buckingham Palace.
French President Emmanuel Macron said although statements he made on NATO on Tuesday "triggered some reactions," he "stands" by them.
Some background: Last month, Macron described the long-time NATO coalition as suffering from "brain death" in part due to a lack of US leadership under Trump — and refused to back down.
Earlier today, President Trump described Macron's comment as “nasty” and “insulting.”
Sitting alongside Trump in London today, Macron said he stands by his comments about NATO — describing it as a “burden we share.”
President Trump and first lady Melania Trump have now arrived at Buckingham Palace. They got there at 6:06 p.m. local time.
There were some supporters chanting “USA” as the President drove through the gates.
The Trumps headed to Buckingham Palace after having tea with Prince Charles and Camilla, the Duchess of Cornwall, at Clarence House.
Here's a photo from their meeting:
German Chancellor Angela Merkel said she’s approaching the NATO summit with optimism.
World leaders are gathering in London to mark the 70th anniversary of the alliance, but tensions have flared between the US and French presidents over comments about the future of NATO.
Earlier today, President Trump said French President Emmanuel Macron was “nasty” when he referred to NATO as suffering from “brain death." The pair also clashed over ISIS and Russia.
Merkel told reporters that leaders have to continually discuss the role of NATO.
“I am very optimistic when it comes to NATO," she said.
President Trump and first lady Melania Trump will soon have tea with Prince Charles and Camilla, the Duchess of Cornwall.
They're en route to Clarence House now, and seem to be running a few minutes behind schedule.
President Trump, while meeting with Canadian Prime Minister Justin Trudeau at the NATO summit in London, attacked House Intelligence Committee Chair Adam Schiff, calling the Democrat a "deranged," "sick" and a "maniac."
Trump was asked about Schiff, who is the chair the House Committee that had been conducting hearings in the impeachment inquiry, at the news conference moments ago, where both American and foreign journalists were present.
"I think he's a maniac," Trump said. "I think Adam Schiff is a deranged human being. I think he grew up with a complex for lots of reasons that are obvious."
Trump continued to attack Schiff, claiming that he "made up" the President's conversation with Ukraine's leader — a call that's at the center of the impeachment inquiry.
"I think he's a very sick man. And he lies. Adam Schiff made up my conversation with the president of Ukraine," Trump said. "We have a perfectly beautiful three or four-page transcription and in the other case a two-page transcription of the conversation."
Trump continued: "This guy is sick. He made up the conversation. He lied. If he didn't do that in the halls of Congress, he'd be thrown in a jail."
Some background here: Trump has repeatedly claimed that Schiff "lied" about his call with Ukraine's president.
At a hearing in September, Schiff mentioned the Trump-Ukraine call, but said he would outline "the essence of what the President communicates," not provide "the exact transcribed version of the call." You can read CNN's full fact check here.
President Trump said next year's G7 summit will be held at Camp David, after previously announcing it would be held at his Florida resort — and then reversing that decision.
"I think it's been more or less announced we'll do it at Camp David," Trump said when asked about the location.
He added that there will be "good access" for the media.
"It will be at camp David, which is a place that people like," Trump said.
In October, Trump announced that next year's G7 economic summit of world powers would be held at his own Trump National in Doral, Florida. But just over 48 hours later, he abruptly reversed course and said the summit would not he held at the resort.
Canadian Prime Minister Justin Trudeau said that while Canada has not yet reached the 2% contribution to NATO, it continually "stepped up" by sending troops to every NATO deployment.
President Trump — who has frequently criticized NATO members for not contributing their "fair" share to the alliance — was asked if there should be a plan to get Canada to 2%.
"We'll put them on a payment plan, you know? I'm sure the prime minister would love that," Trump said.
Trudeau said defense spending is up, and Canada is currently now close to 1.4%.
"They're getting there. They know it's important to do that. And their economy is doing well. They'll get there quickly I think," Trump said.
That's when Trudeau brought up Canadian deployments:
"Canada has been there for every NATO deployment. We have consistently stepped up, sent our troops into harm's way," he said. "We continue to step up — like most of our allies. There are some countries that, even though they might reach the 2%, don't step up nearly as much, and I think it's important to look at what is actually being done, and the United States and all NATO allies know that Canada is a solid, reliable partner and will continue to defend NATO and defend our interests.