Ukrainian president says he is sending a team to meet Russian negotiators in Istanbul, in what would be the first such direct contact in three years.

Putin's absence punctured hopes of a breakthrough in peace efforts that were given a push in recent months by the Trump administration and Western European leaders.

President Volodymyr Zelensky of Ukraine said that if President Trump attended the talks, it would put pressure on Russia’s leader, Vladimir V. Putin, to meet face-to-face.