President Donald Trump on Monday said he was reducing the 50-day deadline he gave Russia over its war in Ukraine to "10 or 12 days," underscoring his frustration with Russian President Vladimir Putin for prolonging fighting between the two countries.

Trump spoke briefly with reporters while welcoming British Prime Minister Keir Starmer and Starmer's wife, Victoria, at Trump Turnberry golf club in Turnberry, Scotland.

"I've spoken to President Putin a lot. I always got along with him very well. But five times, and every time ... four times maybe ... but we've had discussions," Trump said before turning to Starmer. "You and I have had discussions we thought we had settled numerous times. And then President Putin goes out and starts launching rockets into some city like Kyiv, and kills a lot of people in a nursing home or whatever. You have bodies lying all over the street. And I say, that's not the way to do it.

"So we'll see what happens with that. I'm very disappointed. I'm disappointed in President Putin, very disappointed in him. So we're going to have to look, and I'm going to reduce the 50 days that I gave him to a lesser number, because I think I already know the answer."

Trump later said, "Yeah, I'm going to make a new deadline of about 10, 10 or 12 days from today. There's no reason in waiting."

Asked whether he were still open to peace talks with Putin, Trump said: "I'm not so interested in talking anymore."

Ukrainian President Volodymyr Zelenskyy's chief of staff, Andriy Yermak, thanked Trump for the deadline reduction.

"Thank you to US President Donald Trump for his firm stance and clear signal — peace through strength," Yermak said on Telegram. "President Trump said he is reducing the deadline he gave Putin to end the war because he believes the answer is obvious. Putin understands only strength — and this has been clearly and loudly conveyed. This is a principle that is fully shared by the President of Ukraine Volodymyr Zelensky."

Trump set the 50-day deadline earlier this month. The U.S. president has repeatedly voiced exasperation with Putin for continuing attacks on Ukraine despite U.S. efforts to end the war.

Before returning to the White House in January, Trump, who views himself as a peacemaker, had promised to end the three-and-a-half-year-old conflict within 24 hours.

Trump has threatened new sanctions on Russia and buyers of its exports unless an agreement is reached by early September.

But the president, who has also expressed annoyance with Zelenskyy, has not always followed up on his tough talk about Putin with action, citing what he deems a good relationship that the two men have had previously.

"We thought we had that settled numerous times, and then President Putin goes out and starts launching rockets into some city like Kyiv and kills a lot of people in a nursing home or whatever," Trump said. "And I say that's not the way to do it."

Russian spokesperson Dmitry Peskov said Monday there were no plans for a possible meeting between Putin and Trump in Turkey, according to TASS.

Peskov's comment followed Turkish President Tayyip Erdogan on Friday saying he may speak to his Russian and U.S. counterparts this week to see if a leaders' meeting in Istanbul is possible to discuss the war in Ukraine, after Russian and Ukrainian delegations met there last week.

Reuters contributed to this story.