President Donald Trump arrives at the second day of the NATO leaders summit in Watford, England, on December 4, 2019. Christian Hartmann/Reuters

President Donald Trump is at the second day of the NATO leaders‘ summit in England.

He entered the conference on Tuesday triumphant and claiming credit for the defense alliance’s budget changes.

But that success waned quickly as the day went on, as French President Emmanuel Macron openly questioned his claims, Canadian Prime Minister Justin Trudeau appeared to mock him behind his back, and UK Prime Minister Boris Johnson refused to be photographed with him.

All of these leaders had been openly diplomatic and friendly with Trump in the past. Their behavior on Tuesday showed a world no longer bothering to take the US president seriously.

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President Donald Trump entered the NATO summit triumphant, claiming credit for large structural changes in the alliance’s defense spending.

But his first day turned out to encompass one embarrassment after another, with multiple world leaders openly sparring with him and appearing to mock him behind his back — suggesting that nobody is bothering to take him seriously anymore.

Shortly before meeting other Western leaders in London on Tuesday, Trump claimed credit for NATO reducing the US government’s contributions to the group and increasing those from other allies.

Though this plan had been in place since 2014 — when Barack Obama was president — Trump took it as a personal victory because he had long railed against what he perceived as the US’s outsize contribution to the defense alliance.

French President Emmanuel Macron and US President Donald Trump in London on December 3, 2019. Ludovic Marin/Reuters

That feeling of triumph most likely waned quickly, though, as the day went on. Here’s a rundown of Trump’s numerous embarrassments on Tuesday:

He was publicly fact-checked by French President Emmanuel Macron — with whom he has touted having a strong relationship — at their joint press conference. Macron said the Islamic State terrorist group had not yet been defeated, despite Trump’s repeated insistence that it had.

Macron also challenged Trump’s claim that ISIS fighters were „mostly from Europe.“

At a separate press conference with Canadian Prime Minister Justin Trudeau, Trump openly questioned one of NATO’s founding principles, Article 5, which requires members to protect one another if under attack — prompting concern and criticism among NATO officials.

Retired US Army Gen. Wesley Clark, a former NATO commander, told Business Insider’s David Choi that Trump’s comments were „a very rough way to play“ with the alliance’s principles and that „it undercuts deterrence, encourages potential adversaries, and erodes NATO itself.“

Leaders of the NATO alliance countries, and its secretary general, join Britain\'s Queen Elizabeth II and Prince Charles the Prince of Wales, for a group picture during a reception at Buckingham Palace in London, Tuesday Dec. 3, 2019, as they gathered to mark 70-years of the alliance. Back row, from left: Xavier Bettel Prime Minister of Luxembourg; Egils Levits President of Latvia; Gitanas Nauseda President of Lithuania; Dusko Markovic Prime Minister of Montenegro; Erna Solberg Prime Minister of Norway; Mark Rutte Prime Minister of Netherlands; Zuzana Caputova President of Slovakia; Andrzej Duda President of Poland; Antonio Costa Prime Minister of Portugal; Klaus Iohannis President of Romania; Marjan Sarec Prime Minister of Slovenia. Middle row from left: Edi Rama Prime Minister of Albania; Zoran Zaev Prime Minister of North Macedonia; Mette Frederiksen Prime Minister of Denmark; Juri Ratas Prime Minister of Estonia; Emmanuel Macron President of France; Angela Merkel President of Germany; Kyriakos Mitsotakis Prime Minister of Greece; Viktor Orban Prime Minister of Hungary; Katrin Jakobsdottir Prime Minister of Iceland; Giuseppe Conte Prime Minister of Italy; Andrej Plenkovic Prime Minister of Croatia. Seated from left: Sophie Wilmas Prime Minister of Belgium; Rumen Radev President of Bulgaria; Donald Trump President of United States; Prince Charles The Prince of Wales; Jens Stoltenberg NATO Secretary General; Queen Elizabeth II; Boris Johnson Prime Minister of the United Kingdom; Justin Trudeau Prime Minister of Canada; Pedro Sanchez Acting Prime Minister of Spain; Recep Tayyip Erdogan President of Turkey; Milos Zeman President of the Czech Republic. (Yui Mok/Pool via AP) Associated Press

Trump appeared to be roundly mocked by world leaders and royalty behind his back. Though he did not mention Trump by name, Trudeau was recorded on video poking fun at what seemed to be Trump’s impromptu 40-minute press conference, prompting laughter from a group that included Macron, UK Prime Minister Boris Johnson, Dutch Prime Minister Mark Rutte, and Princess Anne.

The British Conservative Party took great pains to distance Johnson from Trump while the two leaders were in the same vicinity, for fear that Trump would jeopardize its chances of winning the coming UK general election next week. (Trump did appear to honor this by saying on Tuesday morning that he had no comment on the election.)

According to Politico’s London Playbook, Johnson was „so keen not to be photographed with the US president that he did not even greet him at the door when he and wife Melania arrived“ at 10 Downing Street on Tuesday night.

A screenshot of a video posted by the Canadian Broadcasting Corporation appears to show world leaders including Emmanuel Macron and Boris Johnson speaking about Donald Trump. Screenshot/CBC

This all shows world leaders aren’t bothering to take Trump seriously anymore.

Macron’s publicly schooling Trump in front of dozens of reporters is a far cry from the two leaders‘ „bromance“ two years ago.

Trudeau’s apparent willingness to mock Trump in front of other world leaders contrasts heavily with the Canadian prime minister’s pledge to himself in 2016 to criticize only the comments, rather than the character, of his American counterpart.

„There was a discipline that I imposed on myself early,“ Trudeau had told the Canadian Broadcasting Corporation journalist Aaron Wherry, who wrote a book about the prime minister.

Johnson’s refusal to be publicly seen with Trump also comes as a huge snub to the US president, who in October had endorsed him in the election.

boris Johnson donald trump Getty

George Conway, the husband of the senior White House counselor, Kellyanne Conway, tweeted in response to the video showing the world leaders on Tuesday, saying Trump was „the laughing stock of the planet.“

„The world thinks you are an incompetent, ignorant, dumb, deranged buffoon — and they are right,“ Conway continued. „And you prove it to them every day.“

Trump, on his end, has put on a veneer of success at the NATO summit on his social-media accounts. It remains unclear how long that will last.