WASHINGTON (Reuters) - The United States on Friday welcomed a “first step” by Saudi Arabia to allow humanitarian aid to reach Yemen and called for negotiations on the country’s conflict.

The coalition fighting the Iran-aligned Houthi movement in Yemen said on Wednesday it would allow aid in through the Red Sea ports of Hodeidah and Salif, as well as U.N. flights to Sanaa, more than two weeks after blockading the country.

About 7 million people face famine in Yemen and their survival is dependent on international assistance.

“Full and immediate implementation of the announced measures is a first step in ensuring that food, medicine, and fuel reach the Yemeni people and that the aid organizations on the frontlines of mitigating this humanitarian crisis are able to do their essential work,” the White House said in a statement.

“We look forward to additional steps that will facilitate the unfettered flow of humanitarian and commercial goods from all ports of entry to the points of need,” it added.

A U.N. spokesman said the Saudi-led coalition had given the United Nations permission to resume flights of aid workers to the Houthi-controlled capital on Saturday, but not to dock ships loaded with wheat and medical supplies.

Reuters reported on Wednesday that U.S. Secretary of State Rex Tillerson asked Saudi Arabia to ease the blockade.

The U.S.-backed coalition closed air, land and sea access on Nov. 6, in a move it said was to stop the flow of arms to the Houthis from Iran. The action came after Saudi Arabia intercepted a missile fired toward Riyadh. Iran has denied supplying weapons.

The White House said it was committed to supporting Saudi Arabia and its Gulf partners “against the Iranian Islamic Revolutionary Guard Corps’ aggression and blatant violations of international law”.

The Saudi-led coalition has been targeting the Houthis since they seized parts of Yemen in 2015, including the capital Sanaa, forcing President Abd-Rabbu Mansour Hadi to flee.

The Houthis, drawn mainly from Yemen’s Zaidi Shi’ite minority and allied with long-serving former president Ali Abdullah Saleh, control much of the country.

The United Nations has been mediating in the conflict without much success.

“The United States continues to believe that this devastating conflict, and the suffering it causes, must be brought to an end through political negotiations,” the White House said.