US President Donald Trump insisted Thursday he would not be intimidated by Russian leader Vladimir Putin on the eve of a high-stakes summit and said Ukraine would be involved in any deal on its fate.

Putin flies to Alaska on Friday at the invitation of Trump in his first visit to a Western country since he ordered the 2022 invasion of Ukraine that has killed tens of thousands of people.

As Russia made gains on the battlefield, the Kremlin said the two presidents planned to meet one-on-one, heightening fears of European leaders that Putin will cajole Trump into a settlement imposed on Ukraine.

Trump insisted to reporters at the White House: "I am president, and he's not going to mess around with me."

"I'll know within the first two minutes, three minutes, four minutes or five minutes...whether or not we're going to have a good meeting or a bad meeting," Trump said.

"And if it's a bad meeting, it'll end very quickly, and if it's a good meeting, we're going to end up getting peace in the pretty near future," said Trump, who gave the summit a one in four chance of failure.

Trump has voiced admiration for Putin in the past and faced wide criticism after a 2018 summit in Helsinki where he appeared to accept the Russian's denials of US intelligence on Moscow's meddling in US elections.

RTHK's Washington correspondent, Simon Marks, said Putin was keen to improve ties with the US.

"It is absolutely apparent from everything that we've heard from the Kremlin that the Russians are very interested in talking to the United States about improving Russia's frozen bilateral relationship with Washington," he told RTHK's Hong Kong Today programme.

"The Arctic is of particular interest to President Putin, who is likely to argue that there are economic cooperation possibilities for the two countries to embark upon together in that particular region and more broadly in terms of getting American investors once again back into the Russian market."

Ukrainian President Volodymyr Zelensky was not invited to the Alaska summit, which he has denounced as a reward to Putin, and has refused Trump's calls to surrender territory.

Trump promised not to finalise any deal with Putin and said he hoped to hold a three-way summit with Zelensky, possibly immediately afterward in Alaska.

"The second meeting is going to be very, very important, because that's going to be a meeting where they make a deal. And I don't want to use the word 'divvy' things up. But you know, to a certain extent, it's not a bad term," Trump told Fox News Radio.

The talks are set to begin at 11:30am (1930 GMT) Friday, local time at the Elmendorf Air Force Base, a major US military installation in Alaska that has been crucial in monitoring Russia.

"This conversation will take place in a one-on-one format, naturally with the participation of interpreters," Kremlin aide Yuri Ushakov told reporters in Moscow. (AFP/RTHK)