A flotilla of nine Iranian military and cargo ships that U.S. officials feared was carrying arms to strife-torn Yemen sailed northeast in the direction of Iran on Friday, a move the Pentagon said helped to ease U.S. concerns.
He declined to say the ships were going back to Iran or headed toward Iran. Warren said the U.S. military did not know their intent and the vessels could turn around at any point.
But Warren did say the shift had helped to ease Washington's concerns.
"I think it's fair to say that this appears to be a de-escalation some of the tensions that were being discussed earlier in the week," Warren said.
President Barack Obama said on Tuesday the U.S. government had warned Iran not to send weapons to Yemen that could be used to threaten shipping traffic in the Gulf. Defense Secretary Ash Carter said on Wednesday the United States
was concerned the ships might be carrying advanced weapons to Houthi rebels there.
A U.S. official, speaking on condition of anonymity, said on Thursday the ships, which were in international waters near the frontier between Oman and Yemen, had turned away from Yemen.
The U.S. Navy sent the USS Theodore Roosevelt and an escort warship into the Arabian Sea earlier this week to support seven U.S. warships already in the area around the Gulf of Aden because of concerns about growing instability in Yemen.
The Iranian-backed Houthis sidelined the Yemeni central government after seizing the capital Sanaa in September. The Shi'ite Muslim Houthis have continued to advance south capturing more territory.
A Saudi-led coalition, supported by the United States, launched an air campaign to destroy heavy weapons controlled by the Houthis that could threaten Saudi Arabia. The Saudis say their aim is to restore President Abd-Rabbu Mansour Hadi.
Saudi Arabia said on Tuesday it was ending its month-long bombing campaign against the Yemeni rebels and shifting to a new phase of its operations in Yemen. Bombing has continued since then, and U.S. officials have said the Saudis had indicated they would continue to bomb as deemed necessary.
(Reporting by David Alexander; Editing by Grant McCool)