In the days following the release of a viral video showing world leaders at the NATO meeting in London making fun of him, Donald Trump shot back at his counterparts. The famously sensitive American president lashed out during a closed-door meeting at the White House with more than a dozen ambassadors to the United Nations present, according to three sources with knowledge of the gathering.

In doing so, he made a number of foreign officials noticeably on-edge and also upended a portion of the meeting meant to focus on world powers’ security cooperation, not personal gripes.

During this private airing of grievances, President Trump repeatedly denigrated the Canadian prime minister behind his back and called the French president a “pain in the ass” while referring to him as “short,” according to an individual who was present for the meeting. Trump also bashed the French leader for not doing enough to help in recent Iran negotiations.

The press was allowed into the room for the beginning of the meeting, during which time the ambassadors each thanked the president for inviting them to the White House and underscored their interest in working with the U.S. on trade, foreign policy, and national security. The permanent representatives hailed from countries such as France, Germany, the United Kingdom, Poland, South Africa, Russia and China.

It wasn’t until after the press left the room that Trump addressed what had become known in the halls of the White House as the “hot mic” story.

French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau, British Prime Minister Boris Johnson, and Dutch Prime Minister Mark Rutte were caught on video talking about President Donald Trump during a NATO reception. The footage circulated widely on social media and by worldwide news outlets shows the leaders gossiping about Trump and his affinity for prolonged news conferences. “He was late because he takes a 40-minute press conference at the top,” Trudeau said apparently referring to Trump’s tardiness. “You just watch his team’s jaws drop to the floor.” Trump addressed the video the next day and called Trudeau “two-faced.”

Over lunch with the ambassadors, President Trump again addressed the video and went on a prolonged tangent, complaining to the diplomats about Trudeau and Macron, according to two sources briefed on the meeting. This lasted several minutes and was enough to derail the ongoing conversation about NATO countries contributing more money to security.

Another individual in the meeting told The Daily Beast that Trump’s comments made ambassadors present “visibly uncomfortable,” especially those whose leaders were involved in the hot-mic video. (The Canadian ambassador to the United Nations was not present at the meeting.)

White House spokespeople did not provide comment for this story as of press time. However, a senior Trump administration official did say that, while not confirming or denying this reporting, the president “shares good relationships with President Macron and Prime Minister Trudeau,” and that “there is little doubt as to the substantive and productive relationships the president has with both leaders.”

Though Trump and Macron used to share a friendly, cordial relationship, those days appear well behind them. And even before the friendship collapsed, the U.S. president would still mean-tweet the French leader from time to time, including when he posted to Twitter a year ago, “The problem is that Emmanuel suffers from a very low Approval Rating in France, 26%, and an unemployment rate of almost 10%.”

But things have been even rockier with Trudeau, who the president has for years regarded as an even bigger pain than Macron. The viral video, in which Trudeau is seen as the ringleader of the Trump mockery, didn’t help.

Aides and longtime associates of Trump say that over the years he has often brought up the Canadian leader in the context of deep annoyance and derision, whether the conversation is about trade negotiations or the president’s displeasure at Trudeau’s insufficiently kind demeanor toward Trump.

In late 2017, Trump sat in the Oval Office, with senior officials such as Ivanka Trump and National Security Council staff, preparing for an upcoming meeting and joint press availability with Trudeau. Soon enough, the president began making fun of the Canadian prime minister and stating how he wished Canadian citizens could see how Trudeau acted in their private discussions, according to a source who was in the room. Trump then clasped his own hands together, began imitating Trudeau using a stereotypically feminine voice, and said, “Oh, Mr. President, we must be sweet to each other, we must play nice,” calling the Canadian leader “such a child” and a “total baby,” the source recounted.

When Ivanka, his daughter and senior adviser in the White House, assured the president that the meeting would be fine and that he only needed to be cordial for roughly an hour, her father told her that he is “always” nice, but that sometimes he needs to be “tough.” President Trump then told the administration officials and national-security aides assembled in the Oval that Trudeau had “no smarts,” zero “toughness,” and that “it’s all fluff,” the source present for this told The Daily Beast.