Vladimir Putin and Donald Trump will meet in the coming days, the Kremlin said on Thursday, as the U.S. president seeks a breakthrough to end the Ukraine war after voicing mounting frustration with his Russian counterpart and threatening him with new sanctions.

Trump became the first sitting US president to meet a North Korean leader when he sat down with Kim Jong-un in Singapore in June 2018. The summit was choreographed as a historic breakthrough, complete with gestures such as handshakes, flags and sweeping promises of denuclearisation.