A proposed summit between Russian President Vladimir Putin and U.S. President Donald Trump has been put on hold after Moscow rejected calls for an immediate ceasefire in Ukraine, according to officials familiar with the stalled negotiations.

The Kremlin’s refusal to halt military operations has cast a shadow over recent diplomatic efforts aimed at brokering a potential peace framework involving European partners and Ukraine. The summit, which was being discussed as part of a broader 12-point peace initiative, is now considered “delayed indefinitely,” one senior diplomat told reporters on Tuesday.

Russia has insisted that any ceasefire must include security guarantees and territorial concessions from Ukraine conditions Kyiv has repeatedly rejected. The Ukrainian government maintains that any agreement must respect its sovereignty and territorial integrity, including the full withdrawal of Russian forces.

President Trump, who was expected to play a central role in facilitating the negotiations, has not publicly commented on the latest setback. However, White House officials confirmed that plans for the summit are currently “on pause” pending further developments on the ground.

The breakdown in talks is a significant blow to growing international hopes for de-escalation, particularly after reports emerged last week of a potential peace board chaired by Trump to oversee conflict resolution efforts.

Fighting along key frontlines in eastern Ukraine has intensified in recent days, further complicating diplomatic efforts.