British Prime Minister Theresa May confronted Russian President Vladimir Putin over the poisoning of a former Russian spy in the UK last year as the two leaders met at the G20 summit in Japan on Friday.
"The prime minister said that the use of a deadly nerve agent on the streets of Salisbury formed part of a wider pattern of unacceptable behaviour and was a truly despicable act that led to the death of a British citizen, Dawn Sturgess," May's office said in a statement.
The British Prime Minister told the Russian president that she wanted the two Russians Britain says are responsible for the attack on Sergei Skripal in Salisbury last year brought to justice.
She also told Putin that "there cannot be a normalisation of our bilateral relationship until Russia stops the irresponsible and destabilising activity that threatens the UK and its allies".
"(She) underlined that we remain open to a different relationship, but for that to happen the Russian government must choose a different path."
Bilateral relations plunged to post-Cold War lows last year when London blamed Moscow for poisoning former Russian spy Sergei Skripal and his daughter Yulia with a nerve agent in the English city of Salisbury.
Moscow denies involvement in the attack, which prompted the biggest wave of diplomatic expulsions between Moscow and the West since the Cold War.
British prosecutors have charged two Russian military intelligence officers, known by the aliases Alexander Petrov and Ruslan Boshirov, with attempted murder in their absence over the attack. They deny involvement.