A top White House official says President Donald Trump's increasingly tough criticism of Volodymyr Zelenskyy reflects the administration’s growing frustration with what they see as the Ukrainian leader creating roadblocks to finding an endgame to Russia’s invasion of Ukraine.

Russia and the U.S. have agreed to start working toward ending the war in Ukraine and improving their diplomatic and economic ties.

The Kremlin says senior American and Russian officials will hold talks on improving their ties and negotiating an end to the war in Ukraine.