Russian President Vladimir Putin has said he does not reject the idea of peace talks on Ukraine.
Speaking after meeting African leaders in St Petersburg, he said African and Chinese initiatives could serve as a basis for finding peace.
But Mr Putin also said there could be no ceasefire while the Ukrainian army was on the offensive.
In the hours after he spoke, Russia said a Ukrainian drone attack on Moscow had damaged two office blocks.
Flights were briefly suspended from Vnukovo Airport, south-west of the city centre, and one person was injured, Russia’s state news agency Tass reported.
Ukraine has not commented on the drone incident.
One eyewitness, who only gave her first name as Liya, told Reuters she could see fire and smoke.”We heard an explosion and it was like a wave, everyone jumped,” she said. “Then there was a lot of smoke and you couldn’t see anything. From above, you could see fire.”
In Ukraine, the north-eastern Ukrainian city of Sumy was hit by rockets, killing one person and injuring five others, the country’s interior ministry said. It said a Russian missile hit an educational establishment on Saturday evening.
On peace talks, both Ukraine and Russia have previously said they will not come to the negotiating table without certain preconditions.
Kyiv says it will not concede any territory but Moscow says Kyiv must accept its country’s “new territorial reality”. Russia invaded its neighbour last year and is occupying territory in the country’s south and east.