Putin says Trump making 'energetic' efforts to end war as summit nears

LONDON -- Russian President Vladimir Putin on Thursday praised President Donald Trump for his efforts to broker an end to Moscow's invasion of Ukraine, as preparations continued for the Friday summit between the American and Russian leaders in Alaska.

The Trump administration "is making quite an energetic and sincere effort, in my opinion, to stop hostilities, to stop the crisis and to reach an agreement that is of interest to all those involved in this conflict," Putin said during a meeting of his top officials to prepare for the Alaska summit, according to a readout published by the Kremlin.

The process could "create long-term conditions of peace both between our countries and in Europe and in the world as a whole, if we reach an agreement on the area of control over strategic offensive weapons by the next stage," Putin added.

Putin's remarks came after Trump on Wednesday warned of "very severe consequences" for Russia if Moscow failed to a ceasefire. Trump did not elaborate on what those consequences would be. When asked if they would include sanctions or tariffs, Trump only said he didn't have to say.

Meanwhile, Ukrainian President Volodymyr Zelenskyy met with British Prime Minister Keir Starmer in London on Thursday as he continued diplomatic maneuvers ahead of Friday's meeting.

Zelensky's visit to London followed his trip to Berlin, Germany, where on Wednesday he met with European leaders -- and spoke virtually with Trump -- to hammer out Ukraine's key demands in any peace negotiations to end Moscow's full-scale invasion, which began in February 2022.

Kyiv set out five key demands. Ukraine will engage in no peace talks without a prior ceasefire, Ukraine must be involved in negotiations and Ukraine will make the decision on any territorial concessions with discussions beginning from the current front lines.

Kyiv has also said it needs solid security guarantees -- with U.S. involvement -- to agree to any deal, and that more sanctions and pressure should be put on Russia if the Alaska summit is unsuccessful.

Zelenskyy and his European backers said that Trump agreed to the negotiating outline.

The president said the call with Zelenskyy was "very friendly," and suggested that a second summit may soon be possible that would bring the Ukrainian and Russian leaders together.

Zelenskyy said he advised Trump and other leaders that Putin is "bluffing" in pursuing peace.

"Putin definitely does not want peace," Zelenskyy said. "He wants the occupation of our country. And we all really understand that. Putin will not be able to deceive anyone. We need further pressure for peace. Not only American, but also European sanctions."

"We talked about the meeting in Alaska," Zelenskyy added. "We hope that the central topic of the meeting will be a ceasefire. An immediate ceasefire."

"The U.S. president has repeatedly said this," Zelenskyy continued. "He suggested to me that after the meeting in Alaska we will have contact. And we will discuss all the results, if there are any. And we will determine the next mutual steps."

Meanwhile, long-range drone and missile attacks continued overnight into Thursday.

Ukraine's air force said Russia launched 45 drones and two missiles into the country overnight, of which 24 drones were shot down or suppressed. Twenty-one drones impacted across 12 locations, the air force said.

Russia's Defense Ministry said its forces shot down 52 Ukrainian drones overnight into Thursday.

Local officials in Rostov-on-Don -- the southern city close to the Ukrainian border which has become a key military headquarters and logistics hub during the invasion -- said a Ukrainian drone struck a residential building injuring at least 13 people.

Ukraine's General Staff said in a post to Facebook that drones struck the Volgograd Oil Refinery Plant in southwest Russia overnight. The refinery produces fuel and other materials "which are critically important for the logistics of the armed forces of Russia," the statement said.

ABC News' Patrick Reevell, Hannah Demissie, Michelle Stoddart, Joe Simonetti, Anna Sergeeva and Othon Leyva contributed to this report.