Feb. 28 was one of the darkest days for Ukraine since Russia’s invasion three years earlier. An Oval Office visit by President Volodymyr Zelensky meant to win favor with President Trump turned into a televised shouting match, prompting Mr. Trump to banish his guest from the White House without even serving him a planned lunch.

Mr. Trump was already a deep skeptic of U.S. support for Ukraine. But after the disastrous meeting with Mr. Zelensky, he accelerated his diplomacy with President Vladimir V. Putin of Russia, drafting a peace plan to end the war in Ukraine that offered major concessions to Moscow. Ukraine’s supporters were in panic.

But there is new hope in Kyiv.

A day after the Trump administration announced an economic deal with Ukraine that gives the United States a stake in its future mineral revenues, analysts say the country’s prospects look brighter than they have in months.

“These are very good signs that something might be shifting,” said Alina Polyakova, the president and chief executive of the Center for European Policy Analysis.

“It does seem like there’s change from the previous approach” by the Trump administration, she said, calling the minerals deal “a win-win for both sides” that Ukraine negotiated “very savvily.”

Mr. Trump and Mr. Zelensky also appeared to have a friendly meeting on Saturday at the Vatican, as Mr. Trump has grown increasingly frustrated with Mr. Putin’s demands in the separate talks to settle the war.