On the eve of peace talks, Ukraine and Russia sharply ramped up the war with one of the biggest drone battles of their conflict, a Russian highway bridge blown up over a passenger train and an ambitious attack on nuclear-capable bombers deep in Siberia.

After days of uncertainty over whether or not Ukraine would even attend, President Volodymyr Zelenskiy said Defence Minister Rustem Umerov would sit down with Russian officials at the second round of direct peace talks in Istanbul on Monday.

The talks, proposed by President Vladimir Putin, have so far yielded the biggest prisoner exchange of the war - but no sense of any consensus on how to halt the fighting.

Amid talk of peace, though, there was much war.