"The United States is very concerned about the Houthis' latest attempt to escalate the war in Yemen, this time by attacking a commercial vessel while it transited one of the world’s busiest shipping lanes, the Bab al-Mandab, in international waters," the release said. "The Iranian regime continues to perpetuate the conflict and provide destabilizing weapons to the Houthis."
The Houthis need to stop the escalation and show they are committed to a peace process, the release added.
Yemen has been engulfed in a violent conflict between the government headed by Yemeni President Abd Rabbuh Mansur Hadi and the Houthi movement, also known as Ansar Allah.
Since March 2015, the Saudi-led coalition of mostly Persian Gulf countries has been carrying out airstrikes against the Houthis at Hadi's request. Millions of Yemenis remain in need of immediate humanitarian aid, according to the United Nations.