MOSCOW (REUTERS) - Russian President Vladimir Putin will deliver a speech on Thursday (April 22) at an online climate change summit hosted by US President Joe Biden, the Kremlin said, despite a deep crisis in relations between Moscow and Washington.

Putin's attendance signals he is still open to dialogue with the United States even though the two countries have imposed new sanctions on each other in the past few days. He has yet to accept or decline a separate invitation from Biden to a bilateral summit.

Biden has invited 40 world leaders to the climate summit, part of his effort to make the fight against global warming a top priority.

Putin, in his speech, will "outline Russia's approaches in the context of forging broad international cooperation aimed at overcoming the negative effects of global climate change," the Kremlin said.

Washington imposed new sanctions on Russia last Thursday for alleged malign activity including interfering in last year's US election, cyber hacking and bullying neighbouring Ukraine.

Russia denied the accusations and retaliated with sanctions of its own the following day.

The United States has warned Russia there will be further consequences if Alexei Navalny, an opposition politician who has been on hunger strike in prison for nearly three weeks, were to die. Russia has said it is ready to impose more "painful" measures against Washington if tensions escalate further.

Relations slumped to a new post-Cold War low last month after Biden said he thought Putin was a "killer" and Moscow recalled its ambassador to Washington for consultations.