Theresa May is to hold talks with Russian President Vladimir Putin when the two leaders attend the G20 summit in Osaka, Downing Street has said.
The Prime Minister's official spokesman said the meeting on Friday did not represent a normalisation of relations with Moscow in the wake of last year's Salisbury nerve agent attack and other "malign" Russian actions.
"The Prime Minister's position on Salisbury and Russia's wider pattern of malign behaviour is well-known," the spokesman said.
"As she has said, we remain open to a different relationship but that can only happen if Russia desists from activity that undermines international treaties and collective security, like the attack in Salisbury.
"This meeting is an important opportunity to deliver this message leader to leader to ensure the UK's position is fully understood.
"Of course, there are matters of international security where we continue to engage with Russia when it is in our national interest to do so.
"This meeting does not represent a normalisation of relations."
The talks in Japan will mark the first time the two leaders have spoken face to face since the last G20 gathering in Argentina at the end of 2018.
Relations between Russia and the West have been severely strained since Moscow's annexation of Crimea in 2014.
Last year Mrs May secured the expulsion of more than 150 Russian diplomats from over 20 countries in response to the the Salisbury attack.
Britain blamed Russia for the attempted poisoning of the former spy Sergei Skripal and his daughter Yulia using the Novichok nerve agent, a claim Moscow strenuously denied.