After dangling the possibility of his attendance, Trump said he would stay away but still wants to meet with Putin, further weakening the Istanbul talks.

Nine people were killed in a Russian drone attack on a minibus carrying civilians on Saturday, Ukrainian authorities said, a day after Moscow and

Ukraine will make securing a ceasefire a priority in expected talks with a Russian delegation in Istanbul on Friday, a Ukrainian diplomatic source said, adding there was also a need for "confidence-building measures".