The U.S. State Department said on Thursday that “some hopeful progress” has been made toward a ceasefire in Yemen, but more commitment was needed from the parties to the civil war.

The comments were in a statement on a just-concluded visit to the region by Timothy Lenderking, the U.S. special envoy for Yemen, aimed at bolstering U.N.-led efforts to end the conflict and stem a growing humanitarian disaster.

The war pits the Iran-aligned Houthi movement against the internationally recognized Yemeni government ousted from the capital, Sanaa, in 2014. The government has been backed since 2015 by a Saudi-led military coalition.

The fighting has killed tens of thousands and pushed the country to the brink of starvation.

Lenderking “devoted extra time in Riyadh and Muscat in an effort to push the parties closer to a ceasefire,” the State Department said. “While there is some hopeful progress, more commitment is needed from the parties.”

The State Department did not elaborate.

Lenderking held talks with the Houthis chief negotiator, Mohammed Abdusalam, in Muscat, the Omani capital, on Feb. 26, although that meeting has not been officially made public by either side.

Saudi Arabia says it seeks a negotiated resolution to the conflict. But in recent days, Riyadh has expressed frustration with intensified missile and armed drone strikes on civilian targets on its side of the border by the Houthis.

In its statement, the State Department called on the Houthis to halt the cross-border attacks and an offensive against the gas-rich Marib region, the last government-held stronghold in northern Yemen.

The United States also urged an end to the cross-border strikes and the Marib offensive in a joint statement issued in London on Thursday with the United Kingdom, Italy, Germany and France.

Reuters