President Trump on Monday acknowledged mass starvation in Gaza after largely deflecting on the issue, even as world leaders and humanitarian organizations warned that more than 20 months of Israeli bombardment and aid restrictions had left nearly two million Palestinians in a hunger crisis.

Speaking to reporters in Scotland during a 75-minute question-and-answer session with Prime Minister Keir Starmer of Britain, Mr. Trump offered a vague promise to open new food sites in Gaza but said nothing about how the United States would get the aid into the largely demolished enclave.

“We’re giving money and things,” Mr. Trump said, adding that he will tell Prime Minister Benjamin Netanyahu of Israel to ensure that food gets to people who need it. “I want to make sure they get the food, every ounce of food.”

For Mr. Trump, who boasts about his transactional approach to deal-making on the world stage, the mass starvation unfolding in Gaza is a test of whether an America First foreign policy can confront one of the biggest humanitarian catastrophes of the 21st century.

When he landed in Scotland for five days of golf and global diplomacy, Mr. Trump’s main concerns about Gaza appeared to be that he had not been thanked enough for providing U.S. aid and that other countries should do more to help the starving children there.

“Nobody said, ‘Gee, thank you very much,’” Mr. Trump complained on Sunday. “And it would be nice to have at least a thank you.”

But after a series of meetings with European leaders, including Mr. Starmer and Ursula Von der Leyen, the president of the European Commission, Mr. Trump began to echo the desperate language of other leaders: There is “real starvation” in Gaza, he said, and the United States would do more to help.

“That’s real starvation stuff, I see it, and you can’t fake that,” Mr. Trump said. “We have to get the kids fed.”

Global crises, especially those unfolding far from the United States, have often been tests of whether American presidents would show moral leadership on the world stage. Failures have been a source of painful regret. In a 1998 visit to Rwanda, President Bill Clinton said the United States and the rest of the world did not do enough to stop the genocide there. As he left office, President Barack Obama questioned why his administration did not do more to plan for the social chaos that engulfed Libya after its leader, Muammar el-Qaddafi, was killed.

Now, it is Mr. Trump’s turn to address the question of whether America still intends to take a leading role among nations in confronting the humanitarian effects of war. He will have to decide whether his preference for focusing on problems at home can justify ignoring horrific images of desperate children dying in Gaza hospitals.

After months of warnings, international agencies, experts and doctors say starvation is now sweeping across Gaza amid restrictions on aid imposed by Israel for months. At least 56 Palestinians died this month of starvation in the territory, nearly half of the total such deaths since the war began 22 months ago, according to data released on Saturday by the Gaza Health Ministry.

To date, the president has appeared wary of using American power to ensure that food, medicine and fuel reach more than two million Palestinians living amid the rubble caused by nearly two years of Israeli bombardment. He has largely blamed Hamas for stealing food that has already been delivered.

But the intervention on Monday from Mr. Starmer, who spoke of a “sense of revulsion” at the suffering of Gazans, appeared to affect Mr. Trump. Mr. Starmer said he discussed a “humanitarian crisis,” including images of starvation, with the American president.

Mr. Trump emerged from the meeting criticizing as ineffective the current aid distribution effort his administration has backed. He said he wanted to create more food sites that were more easily accessible to Palestinians.

“We’re going to set up food centers and where people can walk in and no boundaries. We’re not going to have fences,” he said. “They see the food. It’s all there, but nobody’s at it because they have fences set up that nobody can even get it. It’s crazy what’s going on over there.”

He said Britain would assist the United States in the effort.

It was a notable turn in Mr. Trump’s posture toward Gaza, which has largely been focused in recent weeks on shifting the focus to actions by Hamas.

Three weeks ago, when Mr. Trump met with Mr. Netanyahu at the White House, the president did not dwell on what humanitarian organizations were already signaling was an all-out food crisis in Gaza. Both men praised each other and blamed Hamas’s negotiators for refusing to agree to a cease-fire.

When President Emmanuel Macron of France said last week that reports of imminent starvation had convinced him that it was time to recognize a Palestinian state, Mr. Trump did not echo the concern about people starving.

Instead, he focused on the question of diplomatic recognition of a Palestinian state.

“What he says doesn’t matter,” Mr. Trump said of Mr. Macron’s announcement. “That statement doesn’t carry any weight.”

And as he traveled to Scotland on Friday, Mr. Trump deflected repeated questions about the hunger crisis in Gaza by insisting that food was being delivered by the United States and Israel, but was being blocked by Hamas.

Meeting on Sunday with Ms. von der Leyen, Mr. Trump declared that suffering in Gaza was “not a U.S. problem, it’s an international problem.” He then lamented that he had not been properly thanked for the tens of millions the United States had dedicated toward helping Gaza.

Just days ago, the Trump administration said it had approved $30 million in funding for a fledgling aid distribution system in Gaza backed by Israel and run mostly by American contractors, which has seen deadly violence erupt near its distribution sites.

“Nobody acknowledged it. Nobody talks about it,” Mr. Trump said, adding: “And it makes you feel a little bad when you do that. And you know, you have other countries not giving anything.”

He added, “It would be nice to have at least a thank you.”

Mr. Trump has also claimed that “no other nation gave money.” In fact, as of January, the European Union had spent about $605 million on aid to Gaza since 2023, according to the European Commission.

On Monday, Mr. Trump also indicated disagreement with Israeli officials who have denied that anyone is starving there. He said that the children in Gaza “look very hungry” and that “we have to get the kids fed.”

Mr. Trump said he did not “particularly” agree with a recent assertion by Mr. Netanyahu that there was no starvation in Gaza.

Humanitarian groups around the world say the amount of food needs to increase substantially after months in which the Israeli government imposed a near total blockade of food and medicine into Gaza.