Russian President Vladimir Putin said Thursday that he agrees in principle with a US proposal for a 30-day ceasefire in Ukraine, but he emphasized that the terms are yet to be worked out and noted that any truce should pave the way to lasting peace.

“The idea itself is correct, and we certainly support it," Putin told a news conference in Moscow. “But there are issues that we need to discuss, and I think that we need to talk about it with our American colleagues and partners and, perhaps, have a call with President Trump and discuss it with him."

President Donald Trump said there have been “good signals” coming out of Russia and offered guarded optimism about Putin’s statement. He reiterated that he's ready to speak with Putin and underscored that it was time to end the war.

Putin "put out a very promising statement, but it wasn’t complete,” Trump said Thursday at the start of a meeting at the White House with NATO Secretary General Mark Rutte. “Now we’re going to see whether or not Russia’s there. And if they’re not, it’ll be a very disappointing moment for the world.”

Putin, who launched the full-scale invasion of Ukraine more than three years ago, noted the need to control possible breaches of the truce and signaled that Russia would seek guarantees that Ukraine would not use the break in hostilities to rearm and continue mobilization.

“We agree with the proposals to halt the fighting, but we proceed from the assumption that the ceasefire should lead to lasting peace and remove the root causes of the crisis,” Putin said.

The Russian leader made the remarks just hours after the arrival of Trump’s special envoy, Steve Witkoff, in Moscow for talks on the ceasefire, which Ukraine has accepted. A Kremlin adviser said Putin planned to meet with Witkoff later Thursday.

The diplomatic effort coincided with a Russian claim that its troops have driven the Ukrainian army out of a key town in Russia’s Kursk border region, where Moscow has been trying for seven months to dislodge Ukrainian troops from their foothold.

Putin said it appeared that the US persuaded Ukraine to accept a ceasefire and that Ukraine is interested because of the battlefield situation, particularly in Kursk.

Referring to the Ukrainian troops in Kursk, he questioned what will happen to them if the ceasefire takes hold: “Will all those who are there come out without a fight? Or will the Ukrainian leadership order them to lay down arms and surrender?"

Putin thanked Trump “for paying so much attention to the settlement in Ukraine.”

He also thanked the leaders of China, India, Brazil, and South Africa for their “noble mission to end the fighting,” a statement that suggested those countries could be involved in a ceasefire deal. Russia has said it will not accept peacekeepers from any NATO members to monitor a prospective truce.

Putin's seemingly friendly tone toward the White House reflected the astonishing shift in US relations with Russia and Ukraine since Trump returned to office in January.

Under the administration of former President Joe Biden, the United States was Ukraine's staunchest and most powerful ally and a force for isolating the Kremlin. But Trump's election threw that policy into reverse.

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

The Trump 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 percent of the country.