Nikki Haley denounces Trump’s NATO comments and defends her husband against his attacks.

Nikki Haley condemned former President Donald J. Trump on Sunday for suggesting that he might not defend NATO allies, and that he might even encourage Russia to attack them, if re-elected.

“Don’t take the side of a thug who kills his opponents,” Ms. Haley said on CBS’s “Face the Nation.” “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.”

Ms. Haley was responding to comments Mr. Trump made at a rally on Saturday night, when he recounted a conversation with a foreign leader during his presidency in which he said he might not defend a NATO country against a Russian attack if the country were “delinquent” on funding to the alliance. “No, I would not protect you,” Mr. Trump said he replied. “In fact, I would encourage them to do whatever the hell they want.”

Though there were disputes during Mr. Trump’s administration over some European countries’ spending commitments to their own militaries, there was no debt owed to the alliance.

When the CBS show’s host, Margaret Brennan, asked whether Ms. Haley would “adhere to the premise that an attack on one is an attack on all” if elected president, Ms. Haley said, “Absolutely.”

“We do want NATO allies to pull their weight, but there are ways you can do that without sitting there and telling Russia, ‘Have your way with these countries,’” she said. “If you notice, Russia has never invaded a NATO country. They’ve invaded Georgia, Moldova and Ukraine. They are actually very intimidated by NATO. NATO allows us to prevent war.”

In his rally on Saturday, Mr. Trump also insulted Ms. Haley directly, suggesting that her husband, Michael Haley, a major in the Army National Guard who is deployed to Djibouti, had left the country to avoid being with her.

“This isn’t personal about me and Michael,” Ms. Haley said in the interview on Sunday. “This is about what it says to every member who sacrifices for us. This is about what it says to every military family who sacrifices alongside of them. We can’t have someone who sits there and mocks our men and women who are trying to protect America.”

Ms. Brennan noted that, during his 2016 campaign, Mr. Trump mocked Senator John McCain for having been a prisoner of war and insulted the parents of a soldier killed in combat, but Ms. Haley nonetheless agreed to work for him as ambassador to the United Nations.

“I agreed to serve our country, and I’m proud I got to serve our country,” Ms. Haley replied.

Mr. Trump’s comments on NATO also drew condemnation on Sunday from former Gov. Chris Christie of New Jersey, who was the most outspoken Trump critic in the Republican primary until he ended his campaign last month.

“It’s one thing, and I think it’s right, for a president to say to a NATO member, ‘Hey, you’ve got to pay the dues you need to pay,’” Mr. Christie said on NBC’s “Meet the Press.” “But the problem with Donald Trump is he can’t just stop there. He’s got to say, ‘I would encourage Russia to do whatever the hell they wanted to you.’ That is absolutely inappropriate for a president of the United States or a candidate for president of the United States to be saying, but it is consistent with his love for dictators.”