BRUSSELS (AFP) - European Union foreign policy chief Josep Borrell remains set on visiting Moscow despite a crackdown on protesters and is seeking to visit jailed Kremlin critic Alexei Navalny, a spokesman said Monday (Feb 1).

Mr Borrell is due to head to the Russian capital on Thursday two days after the start of a court hearing that could see President Vladimir Putin's most prominent domestic opponent handed a hefty prison sentence.

The Spanish diplomat has come under pressure from some EU capitals to scrap the trip to Moscow - the first for Brussels' top envoy since 2017 - for fear it could hand the Kremlin a propaganda coup.

But a EU spokesman insisted that the plans to visit Moscow "still stand".

"The continued widespread detention of and use of force against people who are basically trying to express their political opinions is unacceptable," spokesman Peter Stano said.

"This is one of the issues that needs to be raised with the Russian counterparts and this is one of the issues High Representative Borrell wants to raise."

Mr Stano said that "when it comes to Mr Navalny we are of course in touch with his team to see what would be the possibilities for such a meeting to take place".

But he conceded that it will be up to the Russian authorities to agree to the encounter.

"You don't insist, you try to agree with your counterpart on the programme for the visit," he said.

Baton-wielding security forces across Russia on Sunday detained over 5,000 demonstrators calling for the release of Mr Navalny, who has been in custody since returning from Germany following treatment for a near-fatal poisoning.

Prosecutors on Monday backed a request to imprison Mr Navalny for several years for breaching the conditions of an earlier suspended sentence.