President Trump’s envoys Steve Witkoff and Jared Kushner arrived in Ukraine on Sunday, their first trip to the country and the second stop on a diplomatic tour aimed at reviving efforts to end the war between Ukraine and Russia. Mr. Witkoff and Mr. Kushner came straight from Moscow, where they spoke on Saturday with Vladimir V. Putin, the Russian president, for several hours. They arrived in Kyiv by train and were taken by motorcade to meet President Volodymyr Zelensky of Ukraine.

The Ukrainian leader greeted the two Americans on a windy Sophia Square, where hundreds of placards showing the faces of fallen soldiers were on display. Mr. Zelensky hugged both Mr. Witkoff and Mr. Kushner upon their arrival. The men did not make any comments before entering the landmark St. Sophia Cathedral, just across from where a Russian drone recently slammed into the headquarters of Ukraine’s domestic intelligence service headquarters. The meetings come at a dangerous moment in the nearly five-year conflict.

Russia and Ukraine have been escalating, waging an intensifying air war at least in part to try to gain the upper hand in settlement talks. The United States insisted that Ukraine temporarily cease attacks on Moscow and that Russia temporarily halt attacks on Kyiv, Ukraine’s capital, while the men were in those cities. Mr. Zelensky publicly committed to doing so on Friday evening, hours before the envoys landed in Moscow. While they were there, the Kremlin announced that Russia would pause strikes on Kyiv for three days.

Few expect a breakthrough from the U.S. envoys’ trip, which has been billed as the first step toward reviving talks mediated by the Trump administration. Those are expected to resume late this month — days after Russia’s parliamentary election and weeks before U.S. midterm elections. Mr. Trump returned to office last year pledging to end the war in Ukraine swiftly. He enlisted Mr. Witkoff and later Mr. Kushner to assist with negotiations.

By February, Mr. Witkoff and Russian and Ukrainian negotiators had whittled a 20-point peace plan to two key unresolved points: management of a Russian-occupied nuclear power plant and control of territory that Ukraine still holds in the eastern Donbas region. Then the United States and Israel attacked Iran, shifting the White House’s attention away from resolving the war in Ukraine. Mr. Trump told reporters on Friday that Mr. Witkoff and Mr. Kushner were traveling with a proposal to end the war, but he did not provide further details. It was unclear whether it was a new proposal or if the men would be pushing to close the gap on the remaining issues.

Few in Ukraine expect a speedy resolution. The Kremlin has given no indication that it is ready to stop the fighting, and Ukrainian officials say they expect Russian forces to try to inflict as much pain on Ukraine as possible during the winter in hopes of pummeling Kyiv into submission at the negotiating table.