During a political rally on Saturday in South Carolina, Trump complained about what he called "delinquent" payments by some NATO countries and recounted what he said was a past conversation with the head of "a big country" about an attack by Russia on such countries.
Republicans voice strong condemnation as Trump's threat to abandon NATO allies sends shockwaves through the political landscape, raising concerns over international stability and U.S. commitments.
Some of former President Donald Trump's fellow Republicans on Sunday lashed out at him for saying he would not want to protect NATO members from a future attack by Russia if those countries' contributions to the defense alliance were lagging.
"This is why I've been saying for a long time that he's unfit to be president of the United States," former Republican presidential candidate Chris Christie said in an interview with NBC's "Meet the Press" program.
During a political rally on Saturday in South Carolina, Trump complained about what he called "delinquent" payments by some NATO countries and recounted what he said was a past conversation with the head of "a big country" about an attack by Russia on such countries.
"No, I would not protect you. In fact I would encourage them (Russia) to do whatever the hell they want. You gotta pay," Trump said he told the unnamed leader.
The remarks prompted rebukes from the White House, which called them "appalling and unhinged," as well as from other top Western officials.
The failure of many of NATO's 31 members to meet a defense spending target of at least 2% of gross domestic product has long been a source of tension with the United States, whose armed forces form the core the alliance's military power. NATO estimates have shown that only 11 members are spending at the target level.
Former South Carolina Governor Nikki Haley, who is Trump's lone remaining challenger for the 2024 Republican presidential nomination, said: "The last thing we ever want to do is side with Russia."
Interviewed on CBS's "Face the Nation," she added: "Don’t take the side of someone who has gone and invaded a country and half a million people have died or been wounded because of (Russian President Vladimir) Putin" in his war against Ukraine.