US allies have criticised Donald Trump for saying he would “encourage” Russia to do “whatever the hell they want” to any NATO country that doesn’t meet his spending guidelines.

Trump, appearing to recount a meeting with NATO leaders during a political rally in South Carolina, quoted the president of “a big country” that he did not name as asking, “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.”

The NATO treaty contains a provision that guarantees mutual defence of member states if one is attacked.

White House spokesman 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.”

NATO secretary-general Jens Stoltenberg said any suggestion that allies would not defend each other undermined security and “puts American and European soldiers at increased risk”.

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.”

Germany’s foreign ministry posted the message ‘One for all and all for one’ with the hashtag #StrongerTogether on its English language X account following Trump’s comments.

EU Council President Charles Michel said: “Reckless statements on #NATO’s security and Art 5 solidarity serve only (Russian President Vladimir) Putin’s interest.”

Article 5 of the NATO treaty says that an armed attack against an alliance member will be considered an attack against them all, triggering collective self-defence.

EU internal market commissioner Thierry Breton said Trump’s comments were “nothing new under the sun”.

“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 European Commission president Ursula Von der Leyen and a conversation she had with Trump in 2020.

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

With Trump leading Democrat Joe Biden in some polls, European allies worry a Trump victory in November’s presidential elections could jeopardise the US commitment to the alliance.

But Stoltenberg last month said he did not think a second Trump presidency would jeopardise US membership.

Stoltenberg, who has pushed member states to boost defence spending, said European allies were increasing their military contributions and “moving in the right direction”.

Trump has continued to hammer the transatlantic alliance, telling a campaign rally last month that he did not believe NATO countries would support the US if it were attacked.

On Russia’s war in Ukraine, Trump has called for de-escalation and complained about the billions spent so far, although he has put forward few tangible policy proposals.

Since Moscow’s full-scale invasion in February 2022, US aid to Ukraine had totalled about $US75 billion ($115 billion), Stoltenberg said.

Other NATO members and partner states combined have provided more than $US100 billion ($153 billion).

-with AAP