The meeting, held in the Persian Gulf sultanate of Oman, helped facilitate the release Monday of an American freelance journalist, Casey Coombs, who was detained by the Houthis two weeks ago, these officials said.

Three other U.S. nationals continue to be held by the Iranian-backed militia—which took over Yemen’s government in February—although U.S. officials didn’t refer to them as hostages.

The Obama administration sought to use the meeting with Houthi representatives in Muscat for a broader discussion on ways to implement a permanent cease-fire in Yemen and promote a political transition there.

Underscoring the extent of Washington’s involvement with the Houthis, U.S. officials helped facilitate a flight for several members of the rebel group in recent days for the discussions in Oman, which included the Houthi spokesman, a person briefed on the meeting said.