The group said that mediators were working “to remove obstacles and close gaps” after the cease-fire deal with Israel hit a roadblock. Israel has yet to comment.

Mr. Trump made the comments about the hostages while signing executive orders on Monday at the White House. He spoke hours after Hamas said it was delaying the next release of hostages, which was scheduled for Saturday, as a spokesman accused Israel of violating the ceasefire agreement, including by targeting Palestinians in Gaza with airstrikes.

The release of Israeli hostages, and Palestinian prisoners in return, was part of the Gaza ceasefire deal agreed last month.