Assertions by former President Donald Trump that he would encourage Russian attacks against NATO member states that didn’t “pay” were met with swift rebuke from both sides of the aisle Sunday.

Trump, during a Saturday rally in South Carolina, claimed that during his administration he’d informed a NATO nation’s leader he wouldn’t move to defend them should they be attacked by Russia and if they hadn’t paid enough of their GDP for protection.

“One of the presidents of a big country stood up, said, ‘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. You gotta pay your bills,” Trump said to the applause of his audience.

The 45th President’s comments were met with swift backlash from both the left and the right.

Trump’s chief political rival in the 2024 race, former U.N. Ambassador Nikki Haley, defended the long-standing treaty alliance and pointed out that Russia’s President Vladimir Putin is not the sort of world leader the U.S. should to stand beside. While Putin hasn’t been wary about attacking his neighbors, Haley said, he has never attempted to invade a NATO state.

“NATO has been a success story for the last 75 years. But what bothers me about this is, don’t take the side of a thug who kills his opponents. Don’t take the side of someone who has gone in and invaded a country and half a million people have died or been wounded because of Putin. Don’t take the side of someone who continues to lie. I dealt with Russia every day. The last thing we ever want to do is side with Russia,” Haley told CBS.

An attack on any of NATO’s 31 member states would trigger the treaty’s Article 5, which states that an attack on any member country will be treated as an attack on all alliance members.

President Joe Biden’s White House responded by pointing out that, under Biden’s watch, NATO has grown to include more countries than ever before, and, considering Russia’s unlawful invasion of Ukraine two years ago, it comes at a time when the treaty is more important than ever.

“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,” White House spokesperson Andrew Bates said in the statement.

NATO Secretary-General Jens Stoltenberg said that Trump’s comments put both European states and the United States at risk of conflict, avoidance of which is the reason the treaty organization exists in the first place. Trump, who has been a frequent critic of the alliance, would not actually go to the length of withdrawing U.S. support, Stoltenberg guessed.

“Any suggestion that allies will not defend each other undermines all of our security, including that of the US, and puts American and European soldiers at increased risk. I expect that regardless of who wins the presidential election, the US will remain a strong and committed NATO ally,” he said in a statement.

NATO is a collective security organization formed in 1949, during the aftermath of World War II. Member states agree to collectively defend one another in the event of hostile action, and the mutual defense promise served as a check on Soviet aggression through the length of the cold war. Last year, Finland became the 31st state to join the organization, signing the treaty in response to Russia’s aggression in Ukraine.

According to NATO Ambassador Julianne Smith, despite the former President’s long standing assertions to the contrary, treaty signatories have been paying their fair share for defense.

The numbers speak from themselves. Since @NATO Allies agreed that we’d each spend 2% of GDP on our own national defenses, we’ve seen 9 straight years of increases. Europe and Canada have stepped up and will continue to do so, especially in light of Putin’s dangerous attempts to… pic.twitter.com/Icn5OmrV0Y

— Ambassador Julianne Smith (@USAmbNATO) February 11, 2024

“The numbers speak from themselves. Since @NATO Allies agreed that we’d each spend 2% of GDP on our own national defenses, we’ve seen 9 straight years of increases. Europe and Canada have stepped up and will continue to do so, especially in light of Putin’s dangerous attempts to threaten our security,” she wrote on the social media platform formerly known as Twitter.

Constitutional law professor Lawrence Tribe said Trump’s assertions, if made reality, would amount to treason.

This is an announcement by Mr. Trump of intent to commit what Article III defines as “treason” by giving “aid and comfort” to an “enemy,” which Russia would become under Article V of the NATO Treaty by attacking one of our NATO allies. https://t.co/kC4KJgLgEh

— Laurence Tribe (@tribelaw) February 11, 2024

“This is an announcement by Mr. Trump of intent to commit what Article III defines as ‘treason’ by giving ‘aid and comfort’ to an ‘enemy,’ which Russia would become under Article V of the NATO Treaty by attacking one of our NATO allies,” he wrote on Twitter.

But Republican Senator Marco Rubio, speaking Sunday on CNN’s “State of the Union,” said he had “zero concern” about the comments and that Trump was “telling a story” at the rally to drive home a point. The former president “doesn’t talk like a traditional politician. And we have already been through this now,” Rubio said.

Herald wire services contributed.

Russian President Vladimir Putin gestures while speaking during an interview with former Fox News host Tucker Carlson at the Kremlin in Moscow, Russia, last week. (Gavriil Grigorov, Sputnik, Kremlin Pool Photo via AP)