Russian and Ukrainian delegates met in Istanbul on Monday for their second set of direct peace talks, a day after Kyiv launched a shock drone attack on Russia’s nuclear-capable bombers, in an operation that President Volodymyr Zelensky said was a year and a half in the making.

President Volodymyr Zelenskyy said Defense Minister Rustem Umerov would sit down with Russian officials at the second round of peace talks on Monday.

Drones smuggled into Russia hit bases as far away as Siberia and the far east, destroying 41 aircraft that carry cruise missiles and detect enemy planes, said a Ukrainian official.