Ukrainian President Volodymyr Zelenskyy plans to visit Turkey this week to revive talks on ending Russia's invasion, which began nearly four years ago. A U.S. special envoy will join him, but Russia will not send a representative. Earlier talks in Turkey achieved only prisoner exchanges. Heavy U.S. sanctions on Russia's oil industry are set to take effect Friday. On Tuesday, Zelenskyy was in Spain seeking new support. Meanwhile, Ukraine launched aerial attacks on energy infrastructure in the occupied Donetsk region, and Russian drones caused fires in Dnipro. The conflict continues with heavy casualties.