Russian President Vladimir Putin met with U.S. envoy Steve Witkoff to discuss details of the American proposal for a 30-day ceasefire in the war with Ukraine, asking him to convey Moscow’s thoughts to Washington, Kremlin spokesman Dmitry Peskov said Friday.

Putin asked Witkoff late Thursday to give additional messages to U.S. President Donald Trump, Peskov told reporters, after the Russian leader said at a news conference that he supported a truce in principle but set out a host of details that need to be clarified before it is agreed.

Trump said the U.S. held “very good and productive” discussions with Putin the day before. In a post on his Truth Social site Friday morning, Trump said “that there is a very good chance that this horrible, bloody war can finally come to an end,” adding that Ukrainian troops are surrounded by the Russian military.

Ukraine, under severe military pressure on parts of the front line three years after Russia’s full-scale invasion, has already endorsed the truce proposal. Russia’s army has gained battlefield momentum, and analysts say Putin likely will be reluctant to rush into a ceasefire while he feels he has an advantage. The Russian army, backed by North Korean troops, are now close to completely driving Ukrainian forces from their foothold in Russia’s Kursk border region in what would be a major setback for Kyiv.

A possible phone call between Putin and Trump to settle outstanding ceasefire issues could be arranged after Witkoff delivers the messages in Washington, Peskov said. “There is an understanding on both sides that such a call is needed,” Peskov said.

“There are certainly some grounds for cautious optimism,” Peskov said of the ceasefire proposal. “A lot still needs to be done, but the president has shown solidarity with President Trump’s position.”

U.S. officials have said Washington was set to discuss technical issues related to a possible ceasefire next week. Given the range of issues on the table, and the sharp differences between what Moscow and Kyiv want, it could potentially take weeks or months for the guns to fall silent.

Trump vowed during his election campaign to settle the war in 24 hours, but in January he changed that timeframe, voicing hope that peace could be negotiated in six months.

Putin’s apparently amicable tone toward the White House reflects the remarkable shift in U.S. relations with Russia and Ukraine since Trump returned to office in January. Former President Joe Biden had sought to isolate Putin.

Trump has threatened both Russia and Ukraine with punitive measures if they don’t engage with his peace efforts.

Trump briefly cut off critical military aid and intelligence sharing in an apparent effort to push Kyiv to enter talks on ending the war. Ukrainian President Volodymyr Zelenskyy had a tense meeting at the White House on Feb. 28 in which Trump questioned whether Ukraine wanted to halt the war.

Trump has raised the possibility of tightening sanctions on Russia, though his administration has also repeatedly embraced Kremlin positions on the conflict, including indicating that Ukraine’s hopes of joining NATO are unlikely to be realized and that it probably will not get back the land that Russia’s army occupies, which amounts to nearly 20% of the country.

Meanwhile, Russian air defenses downed four Ukrainian drones attacking the Russian capital early Friday, Moscow Mayor Sergei Sobyanin said. One damaged the roof of an apartment building a few kilometers (miles) from the Kremlin.

Several other buildings were lightly damaged by drone fragments, but there were no injuries, according to emergency officials.