The deepening humanitarian crisis in the Gaza Strip is driving a wedge between Ron DeSantis and Nikki Haley, two of the leading Republican presidential candidates, who deviated sharply on Sunday over whether the United States should help Palestinian refugees from the region ahead of an expected Israeli invasion.

In an appearance on the CBS morning show “Face the Nation,” Mr. DeSantis, the Florida governor, doubled down on remarks he had made one day earlier in Iowa, espousing a hard-line opposition toward helping civilians who have been thrust into the middle of the conflict.

“They teach kids to hate Jews,” he said. “The textbooks do not have Israel even on the map. They prepare very young kids to commit terrorist attacks. So I think it’s a toxic culture.”

Ms. Haley, the former United Nations ambassador under President Donald J. Trump, pushed back against that view during a CNN interview on Sunday with Jake Tapper on “State of the Union.”

“America has always been sympathetic to the fact that you can separate civilians from terrorists,” she said after being shown a clip of Mr. DeSantis’s initial comments on Saturday.

Nearly one million people are grappling with shortages of food, clean water and shelter in Gaza, which is bracing for a land invasion by Israel in retaliation for the Oct. 7 attacks and the taking of hostages by Hamas, an Iran-backed militant group.

Mr. DeSantis argued on Sunday that it would be detrimental to the United States to “import” large numbers of refugees and would fuel antisemitism, echoing comments he made about people in Gaza the day before that drew scrutiny.

At a campaign event on Saturday, Mr. DeSantis said, “If you look at how they behave, not all of them are Hamas, but they are all antisemitic. None of them believe in Israel’s right to exist.”

He added: “The Arab states should be taking them. If you have refugees, you don’t fly people in and take them into the United States of America.”

When the CBS anchor Margaret Brennan pointed out to Mr. DeSantis that Arabs are Semites and replayed his remarks, he stood by his words.

“There was a lot of celebrating of those attacks in the Gaza Strip by a lot of those folks who were not Hamas,” he said.

Ms. Brennan suggested that it was a remote possibility that refugees from Gaza could resettle in the United States, saying that they could not even evacuate from their immediate area. Still, Republicans have used the broader conflict to frame their postures on military action and humanitarian aid.

In the House, Representatives Tom Tiffany of Wisconsin and Andy Ogles of Tennessee, both Republicans, have announced that they plan to introduce a bill they say would block the Biden administration from issuing visas to Palestinian passport holders.

Mr. DeSantis, who served in the Navy’s Judge Advocate General Corps in Iraq, was also asked whether he would advise the Israeli military to stop its attacks on the infrastructure that provides water and electricity to Gaza.

“I don’t think they’re under an obligation to be providing water and these utilities while the hostages are being held,” he said.

Ms. Haley struck a more sympathetic chord earlier on Sunday, saying that large percentages of Palestinians and Iranians did not support the violence being perpetrated against one another.

“There are so many of these people who want to be free from this terrorist rule,” she said.

While the Republican candidates have expressed solidarity with Israel in the wake of the Hamas attacks, they have also clashed with one another over who is most loyal to Israel, America’s closest Middle East ally, and what the role of the United States should be in conflicts overseas.

Ms. Haley on Sunday continued to condemn Mr. Trump, her former boss and the Republican front-runner, for referring to Hezbollah, the Iran-backed militant group, as “very smart” while criticizing Israel’s prime minister and Israeli intelligence. She accused Mr. Trump of emboldening U.S. adversaries and drawing attention to himself.

“You don’t go and compliment any of them because what that does is that makes America look weak,” she said on CNN, adding: “This isn’t about Trump. It’s not about him.”

A spokesman for the Trump campaign did not immediately respond to a request for comment on Sunday.

Ms. Haley also leveled fresh criticism toward President Biden, saying that he should never have agreed to free up $6 billion in frozen oil revenue money for Iran for humanitarian purposes as part of a hostage release deal that was announced in August.

Facing blowback over the money’s release, the Biden administration and Qatar agreed last week to deny Iran access to the funds, which White House officials had said had not been spent.

“You empowered Iran to go and strengthen Hamas, strengthen Hezbollah, strengthen the Houthis to spread their terrorist activity,” Ms. Haley said.

The White House did not immediately respond to a request for comment on Sunday.

Haley Johnson contributed reporting from Creston, Iowa.