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.

Ukraine’s President Volodymyr Zelensky raised the stakes ahead of a potential meeting with Vladimir Putin in Turkey on Thursday by saying he wouldn’t hold talks with any Russian representative other than the president himself.