Joseph Biden (Photo Credit: AFP/Mark Makela)

Russia said on Monday that a U.S. refusal to organise live online talks between Vladimir Putin and Joe Biden after the U.S. president said he believed his Russian counterpart was a killer amounted to a serious missed opportunity.

Putin said last week that he and Biden should hold such talks in the coming days after diplomatic ties sank to a new post-Cold War low following Biden’s comments in an ABC interview.

“We note with regret that the American side has not supported (Putin’s) proposal to hold talks with U.S President Biden…to discuss problems that have built up in bilateral relations and also the theme around strategic (nuclear) stability,” Russia’s foreign ministry said in a statement.

“Another opportunity has been missed to search for a way out of the dead end in Russian-American relations caused by Washington. Responsibility for this lies entirely with the United States.”

Russia’s ambassador to the United States, Anatoly Antonov, arrived in Moscow on Sunday for discussions on how to address sliding U.S.-Russia relations after Moscow recalled him for talks.

On Monday, Antonov was spotted leaving the foreign ministry building, but declined to comment, the TASS news agency reported.

Reporting by Anton Kolodyazhnyy/Alexander Marrow; Editing by Andrew Osborn