When President Trump   holds a phone call with Vladimir Putin on Monday, he will be facing a Kremlin leader pursuing twin goals: slow-walking peace talks and simultaneously portraying himself as a peace-loving president who could be a valuable trade partner of the U.S.

Russia has shown no sign of letting up in its assault on Ukraine. Moscow launched one of the largest aerial barrages of the war overnight into Sunday, deploying 273 drones across Ukraine. The attacks killed at least one person and injured three in Kyiv, including a 4-year-old.

Trump sounded optimistic on Saturday as he announced plans for his third official call with Putin this year, saying he would speak with Ukrainian President Volodymyr Zelensky and NATO members afterward. “Hopefully it will be a productive day, a ceasefire will take place,” he wrote on his Truth Social network.

Zelensky met with Vice President JD Vance and Secretary of State Marco Rubio on the sidelines of Pope Leo XIV’s inauguration Mass on Sunday. The meeting was the first between the Ukrainian leader and Vance since a fiery Oval Office clash earlier this year.

Zelensky described it as a good meeting in a post on X Sunday, saying the discussion focused on the negotiations in Istanbul , sanctions and trade. The Ukrainian president said he stressed the need for further sanctioning Russia and underscored the importance of a full and unconditional cease-fire.

Rubio struck a more cautious note than Trump ahead of Monday’s call with Putin, signaling that no breakthroughs were in the offing. In an interview on Face the Nation on Sunday morning, he said that the U.S. would need to evaluate separate peace proposals from Russia and Ukraine after the two sides had met in Istanbul on Friday.

“We’re trying to achieve peace and end a very bloody, costly and destructive war,” he said. “So there’s some element of patience that is required.”

Putin’s handling of Trump in the first months of his presidency has turned into a study of just how far the Russian president can test the U.S. president’s patience as he frustrates Trump’s campaign promise of brokering a quick end to the war in Ukraine. While Trump has at times expressed annoyance at Putin , he so far has balked at deploying more economic sanctions against Russia.

Talks on Friday between Kyiv and Moscow representatives in Istanbul delivered little progress and showed that Putin is sticking to his maximalist demands in the war: achieving a weakened Ukraine dominated by Moscow. Russia rejected the demand by Kyiv and its allies to have a cease-fire in place before negotiating a long-term peace.

At the same time, the Trump administration can now say that Russia and Ukraine are at least engaging in negotiations. In his comments Sunday, Rubio said the talks “were not a complete waste of time” because they prompted an exchange of prisoners between Russia and Ukraine, and that proposals for a cease-fire could soon lead to broader negotiations.

“Putin aims to stall by avoiding a cease-fire and to keep Trump’s trust by not losing the chance to maintain good relations with the U.S.,” Andrei Kolesnikov , a political analyst based in Moscow. “Putin will try to convince Trump that he remains committed to peace, but the Russian side will continue to reject the ‘first cease-fire, then negotiations’ formula.”

Since his election, Trump’s interactions with the Kremlin have allowed him to claim incipient progress but no peace deal. After a phone call with Putin in February, the U.S. and Russia announced the opening of talks in Saudi Arabia led on the U.S. side by Trump’s close personal friend, Steve Witkoff , whom he appointed as special envoy . Talks have been inconclusive but provoked tensions with European allies and Ukraine, who worried that Trump was cutting a peace deal with the Kremlin without their input.

After another phone call in March, Trump announced that Putin agreed to a partial cease-fire against Ukraine’s energy infrastructure. But the cease-fire never stuck, and Moscow was resistant to any wider truce.

The Kremlin all the while has been appealing to Trump’s commercial instincts by touting the economic rewards of normalizing relations between the U.S. and Russia. Witkoff has traveled to Russia and met four times with Putin, coming out of talks echoing the Kremlin’s talking points about the origins of the war in Ukraine.

Putin has sent his own special envoy, Kirill Dmitriev , to the U.S. The Trump administration granted him a waiver on sanctions so he could travel last month to Washington, where he dangled the prospect of new economic ventures, including oil and Arctic partnerships.

Eric Green , a former White House adviser for Russia during the Biden administration, said Putin will likely try more of the same in the phone call with Trump on Monday, telling Trump that talks in Istanbul last week marked progress and then trying to shift the conversation toward economic deals.

“Obviously Putin wants a free hand in Ukraine, and he wants normalization of relations with the U.S.,” Green said. In his post Saturday, Trump noted that beyond the war he is also looking to discuss trade with Putin on the phone call.

Despite more than 900,000 of its troops killed or wounded in Ukraine, according to Western estimates, Russia has continued to dig in with its war aims.

In Friday’s talks, the Kremlin representatives countered Ukraine’s request for an unconditional cease-fire with a demand for Kyiv’s forces to withdraw from the portions of the Zaporizhzhia, Kherson, Donetsk and Luhansk regions still under Ukrainian control. Moscow declared those regions part of Russia in late 2022 after holding a sham referendum but since then has made limited progress in its attempts to fully conquer them.

Russia also continues to insist on eliminating the “root causes” of the conflict, Kremlin shorthand for Kyiv’s existence as a sovereign state and the North Atlantic Treaty Organization’s expansion in the former Eastern bloc.

Hours after the Istanbul meeting, a Russian drone struck a bus in the northeastern Ukrainian region of Sumy, killing nine people and injuring four.

In Kyiv, the air-raid alert sirens began wailing again around midnight on Saturday night. The attack continued for nine hours, until authorities gave the all-clear at 8:54 a.m. Sunday. The bombardment killed a 27-year-old woman and shattered windows and damaged buildings across the capital, authorities said.

Still, Putin has continued to engage with Trump, aware of the consequences of a breakdown in the relationship. Trump has threatened new sanctions several times and questioned in one social-media post whether Putin is “tapping me along.”

At the same time, Sen. Lindsey Graham (R., S.C.), a close ally of Trump, is forging ahead on a plan to impose steep tariffs on countries that buy Russian oil, gas and uranium, potentially putting pressure on Moscow’s most important revenue stream.

Any new penalties would come at a difficult time for the Russian economy. After weathering Western sanctions throughout the conflict by shifting the economy to a war footing and relying on ample oil exports, Moscow is now facing an abrupt slowdown.

“A potential economic deal with Trump is important for Russia because Putin’s old energy model is not bringing enough money into the budget and Russia is sinking into stagflation,” Kolesnikov, the political analyst, said.

Write to Alan Cullison at alan.cullison@wsj.com and Georgi Kantchev at georgi.kantchev@wsj.com