WASHINGTON (Kyodo) -- U.S. President Donald Trump said Thursday he believes Russian President Vladimir Putin will not invade Ukraine again if a peace deal is struck, dismissing the need to provide security guarantees to the war-torn country.

"I have confidence that if we make a deal, it's going to hold," Trump said as he hosted British Prime Minister Keir Starmer at the White House, with his administration's high-speed attempt to end the war in Ukraine fueling both hopes and worries among world leaders.

Trump said he has "a very good relationship" with Putin and he believes he also does with Ukrainian President Volodymyr Zelenskyy.

Trump backpedaled from his earlier assertion that Zelenskyy is a "dictator," a day before the Ukrainian president's visit to Washington, during which they are set to sign an agreement that would enable the United States to access Ukraine's rare earths and other critical minerals.

"Did I say that? I can't believe I said that," Trump said.

Starmer's trip to Washington came a few days after a visit by French President Emmanuel Macron, with both leaders cautioning Trump not to side with Russia in bringing the conflict to a close.

For a lasting peace in Ukraine, Zelenskyy and European leaders have said there should be U.S.-backed security guarantees.

But a senior Trump administration official said Thursday the minerals deal "does not include any specific guarantee of funding for future war fighting, nor does it commit any U.S. personnel in the region."

Trump also said before his talks with Starmer that Ukrainian membership of NATO, a longtime aspiration, is "not going to happen."

Trump has reiterated that his primary goals are to end the three-year-old war and stop the United States from providing any more money to Ukraine.

The agreement on Ukraine's critical minerals, described by U.S. officials as an "economic partnership," is designed to recoup some of the American taxpayer money provided by Washington in military support to Kyiv since the start of Russia's full-scale invasion in February 2022.

At a joint press conference following his discussions with Trump, Starmer welcomed the U.S. president's "deep and personal commitment" to bringing peace to Ukraine, but warned it cannot be done in a way that "rewards the aggressor."

"You have created a moment of tremendous opportunity to reach a historic peace deal, a deal that I think would be celebrated in Ukraine and around the world," he said. "That is the prize, but we have to get it right."

The British prime minister said the outcome of the war in Ukraine should not provide encouragement to regimes like Iran, and that "history must be on the side of the peacemaker, not the invader."

While working closely with other European countries, Starmer said Britain is ready to "put boots on the ground and planes in the air" to ensure peace in Ukraine will last.