As Yemen’s Houthi rebels made significant gains in the face of Saudi-led air strikes Friday, the White House strongly condemned the ongoing advancement against the country’s elected government.

Bernadette Meehan, spokesperson for the National Safety Council, said in a statement that U.S. officials have been in close contact with Yemen’s President Hadi and partners in the region. “In response to the deteriorating security situation, Saudi Arabia, Gulf Cooperation Council (GCC) members, and others will undertake military action to defend Saudi Arabia’s border and to protect Yemen’s legitimate government,” Meehan said. “As announced by GCC members earlier tonight, they are taking this action at the request of Yemeni President Abdo Rabbo Mansour Hadi.”

Earlier Friday, Shi’ite Muslim Houthi fighters sized the port of Shaqra, 60 miles east of Aden, to gain what Reuters described as their first foothold on Yemen’s Arabian Sea coast. A Saudi-led air campaign has gone on for three nights, but Yemen’s government said it would not last.

The White House urged the Houthis to halt immediately their “destabilizing military actions” and resume negotiations to seek a peaceful solution.   

“The international community has spoken clearly through the U.N. Security Council and in other fora that the violent takeover of Yemen by an armed faction is unacceptable and that a legitimate political transition -- long sought by the Yemeni people -- can be accomplished only through political negotiations and a consensus agreement among all of the parties,” Meehan said.

Read the full statement here.