The Finnish capital of Helsinki is being considered as a location for a summit between U.S. President Donald Trump and Russian President Vladimir Putin, a senior U.S. official said on Tuesday.

U.S. Secretary of State Mike Pompeo said over the weekend it was likely Trump would meet his Russian counterpart "in the not too distant future" following White House national security adviser John Bolton's visit to Moscow this week.

The senior U.S. official, speaking on condition of anonymity, said while Helsinki was the likeliest choice, the final decision depended on the outcome of talks Bolton is having with the Russians.

Vienna had been also discussed as a potential site for the meeting, but officials said that idea has been abandoned.

The highly anticipated Trump-Putin meeting is likely to take place after a July 11-12 NATO summit in Brussels that Trump is expected to attend. Trump is also expected to visit London for talks with British Prime Minister Theresa May on the trip.

Trump, who has said he wants better relations with Russia, last met Putin in November in Vietnam on the sidelines of an Asia-Pacific summit.

A probe of Russia's alleged involvement in the 2016 U.S. election has hung over Trump's presidency. U.S. special counsel Robert Mueller is investigating whether Trump's 2016 presidential campaign colluded with Russia.

Moscow denies meddling in the U.S. election and Trump denies any collusion took place.