Donald Trump is soon going to be faced with a difficult decision in his push to end Russia’s war in Ukraine, according to some European and U.S. officials briefed on his team’s negotiations with the Kremlin.

Following three days of talks in Saudi Arabia that ended Tuesday, Russian officials said they want relief from some sanctions before implementing an agreed ceasefire in the Black Sea.

That left members of the U.S. delegation frustrated as they said the Russians weren’t sticking to commitments they’d made, according to several people with knowledge of their discussions. Several officials from both the U.S. and Europe suggested that the Kremlin is playing games with the Americans and wondered how long Trump would tolerate that.