Donald Trump told top European officials while he was U.S. president that the United States would never help Europe if it came under attack, according to a high-level EU official.

Thierry Breton, a French commissioner who is responsible for the European Union’s internal market, said Trump made the remarks to European Commission President Ursula von der Leyen at the World Economic Forum in Davos in January 2020.

Breton recounted his recollection of the meeting, which he also attended, at a panel discussion in Brussels on Tuesday. His comments prompted sharp criticism of Trump on Wednesday from U.S. President Joe Biden’s campaign for re-election.

“You need to understand that if Europe is under attack, we will never come to help you and to support you,” Breton quoted Trump as saying during the Davos meeting.

“By the way, NATO is dead, and we will leave, we will quit NATO,” Trump also said, according to Breton, speaking at an event hosted by the Renew Europe political party at the European Parliament.

“And by the way, you owe me $400 billion, because you didn’t pay, you Germans, what you had to pay for defense,” Breton quoted Trump as saying.

Asked whether von der Leyen’s recollection of Trump’s remarks matched those of Breton, a spokesperson for the European Commission president declined to comment.

“Out of principle the President NEVER discloses what her interlocutors have told her during closed door meetings. So we are not going to comment either way,” the spokesperson said in an email.

Phil Hogan – an Irishman who was European Trade Commissioner and, according to Breton, also attending the Davos meeting – did not immediately reply to an emailed request for comment.

Trump is the frontrunner to be the Republican nominee in the 2024 presidential election, with opinion polls predicting a tight contest against Biden in the November vote.

A spokesperson for Biden’s campaign said: “The idea that he would abandon our allies if he doesn’t get his way underscores what we already know to be true about Donald Trump: The only person he cares about is himself.”

Trump’s campaign did not immediately respond to a request for comment.

During his first term from 2017 to 2021, Trump repeatedly clashed with traditional allies over trade and defense spending.

Trump himself has offered few clues about the foreign policy he would pursue were he to win in 2024 beyond broad claims like ending the Ukraine war in 24 hours, prompting concern in European capitals.

During a second term, he would likely install loyalists in key positions, allowing him more freedom to enact isolationist policies and whims, according to current and former aides and diplomats.