The US urged the Houthis to halt their attacks on Marib if they were serious in their efforts to end the war and achieve peace. "The United States urges the Houthis to halt their advance on Marib and cease all military operations and turn to negotiations," a statement released by the US State Department said. "The Houthis' assault on Marib is the action of a group not committed to peace or to ending the war afflicting the people of Yemen," the statement added, pointing out that the UNOCHA estimates about one million Yemenis have sought refuge in Marib since the beginning of the war to escape Houthi violence. In the statement, the US also said: "This assault will only increase the number of internally displaced persons and exacerbate the humanitarian crisis in Yemen, already home to the world's worst humanitarian catastrophe." The statement concluded: "If the Houthis are serious about a negotiated political solution, they must cease all military advances and refrain from other destabilizing and potentially lethal actions, including cross-border attacks on Saudi Arabia." "They must commit to constructively participate in the UN-led political process and engage seriously in the diplomatic effort led by U.S. Special Envoy for Yemen Tim Lenderking. The time to end this conflict is now. There is no military solution."