U.S. national-security adviser John Bolton says there is no need for Ukrainian President Volodymyr Zelensky to "rush" into any course of action regarding Russia’s involvement with Russia-backed forces in eastern Ukraine.

"I think, from the perspective of a new government in Ukraine, President Zelensky would be well-advised to look at how to unfold a strategy of dealing with the Russians very carefully," Bolton told RFE/RL in a wide-ranging interview on August 27 in Ukraine's capital, Kyiv.

“I don't think there is any reason to rush it into one course of action or another…. I think working this through over a period of time makes sense for the new government in Ukraine."

"I don't suppose that the Europeans are going to have a solution that is readily apparent," he added in reference to the so-called Normandy format of negotiations aimed at ending the Ukraine conflict.

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After being elected in April this year, Zelensky called for a four-way meeting with fellow Normandy format participants Russia, Germany, and France to revive peace talks with Kremlin leader Vladimir Putin.

Moscow has said there is interest in renewing peace discussions, but it did not specify a time frame.

On August 26, French President Emmanuel Macron said the Normandy format leaders will hold a summit next month.

"We think that the conditions exist for a useful summit," Macron said at the end of a Group of Seven (G7) meeting in the southwestern French coastal resort of Biarritz.

Asked if Washington would want to join in Normandy format talks, Bolton did not answer directly, but said there is "significant American interest" in existing issues between Kyiv and Moscow.

"I think that is why we should consider, if President Zelensky wants us to be involved [in talks with Russia], whether we should do it."

Bolton also voiced U.S. concern about Russia's military buildup in the Black Sea, including in Crimea, which has been unlawfully annexed by Moscow from Ukraine.

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"The Black Sea has a number of NATO allies that also are part of it," Bolton said, adding, "We expect to see access across the Black Sea maintained for all the littoral states and other traders who use the Black Sea."

He said the United States was monitoring Russian activities in other parts of the world as well.

Bolton’s visit is the first to Ukraine by a top U.S. official since Zelensky’s election in April. He is scheduled to meet with the Ukrainian leader on August 28, according to Ukrainian media reports.

Upon his arrival, Bolton told reporters that "for me, this is an opportunity to talk about some priorities we have and really also, because of the new administration here, to hear their priorities."