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

The president said he's optimistic about Thursday's expected talks between Vladimir Putin and Volodymyr Zelensky in Istanbul.

By Anton Kolodyazhnyy, Steve Holland and Lidia Kelly MOSCOW/WASHINGTON (Reuters) -U.S. President Donald Trump's offer to join proposed Ukraine-Russia peace talks triggered a flurry of diplomacy as powers from Europe to the Middle East sought a possible path out of the deadliest conflict in Europe since World War Two.