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.

Ten days of intense diplomatic maneuvers by Europeans and the US ahead of the meeting in Turkey were insufficient to reach a deal, as the differences between the two belligerent parties appear insurmountable.

Russian representatives have voiced several demands to the Ukrainian delegation during a closed meeting in Istanbul on 16 May, setting out the conditions under which Moscow is ready to cease fire. Among them are Ukraine's renunciation of territories and claims for reparations.