Russian and Ukrainian negotiators will meet in Istanbul on Friday for their first peace talks in more than three years as both sides come under pressure from U.S. President Donald Trump to end Europe's deadliest conflict since World War Two.

ISTANBUL − Russia's Vladimir Putin spurned a challenge to meet face-to-face with Volodymyr Zelenskyy in Turkey, instead sending a second-tier delegation to planned peace talks, while Ukraine's president said his defence minister would head up Kyiv's team.

Marco Rubio says the "only way we’re going to have a breakthrough here is between President Trump and President Putin".