EU Internal Market Commissioner Thierry Breton was asked in an LCI television interview about the remarks on Saturday by Trump, who is likely to be the Republican nominee in this year's U.S. presidential election.

"We cannot flip a coin about our security every four years depending on this or that election, namely the U.S. presidential election," Breton said, adding European Union leaders understood the bloc needed to boost its own military spending and capacities.

Polish Defence Minister Wladyslaw Kosiniak-Kamysz also weighed in.

"NATO's motto 'one for all, all for one' is a concrete commitment. Undermining the credibility of allied countries means weakening the entire NATO," he wrote on social media platform X.

"No election campaign is an excuse for playing with the security of the Alliance."

Officials at NATO headquarters in Brussels did not immediately respond to a request for comment. The NATO treaty contains a provision that guarantees mutual defence of member states if one is attacked.

Trump, speaking during a political rally in South Carolina on Saturday and appearing to recount a meeting with NATO leaders, quoted the president of "a big country" that he did not name as asking, "Well sir if we don't pay, and we're attacked by Russia - will you protect us?"

"I said: 'You didn't pay? You're delinquent?' He said: 'Yes, let's say that happened.' No I would not protect you. In fact I would encourage them to do whatever the hell they want. You gotta pay."

"We have heard that before... Nothing new under the sun", Breton said, adding:

"He maybe has issues with his memory, it was actually a female president, not of a country, but of the European Union", Breton said, referring to the bloc's Commission President Ursula Von der Leyen and a conversation she had with Trump in 2020.

White House spokesperson Andrew Bates, asked about Trump's comments, said, "Encouraging invasions of our closest allies by murderous regimes is appalling and unhinged - and it endangers American national security, global stability and our economy at home."

(Reporting by Tassilo Hummel; Additional reporting by Anna Wlodarczak-Semczuk; Editing by Frances Kerry)