mccain
U.S. Sen. John McCain attends a panel discussion at the Munich Security Conference in Munich, Feb. 14, 2016. REUTERS/Michael Dalder

U.S. Republican Sen. John McCain said on Sunday he would subpoena 10 U.S. sailors to testify about their brief detention by Iran if the Obama administration does not provide the findings of an investigation into the incident by March 1.

“It’s an option that I do not want to exercise,” McCain, who chairs the Senate Armed Services Committee, told reporters as he was returning to the United States from an international security conference in Germany.

The sailors were detained by the Islamic Revolutionary Guard Corps after their two patrol boats strayed into Iranian waters on Jan. 12. U.S. officials later blamed a navigational problem.

The Americans were freed the next day after U.S. Secretary of State John Kerry intervened with Iranian Foreign Minister Mohammad Javad Zarif, averting a diplomatic crisis just days before implementation of the Iran nuclear deal and the lifting of international sanctions on Tehran.

Iranian media broadcast videos of the detainees, including scenes in which Revolutionary Guards personnel trained weapons on the sailors as they kneeled.

The Obama administration has said the sailors’ speedy release showed the power of diplomacy and the promise of its new engagement with Iran.

Republicans have been critical of the deal with Iran, and some say the detainment of the sailors showed how little regard Iran had for the United States.

McCain said he had been told the sailors were still being debriefed, but added that he assumed that administration members were “dragging their feet” in completing an investigation into the incident, which he accused Iran of exploiting for propaganda purposes.

“I guarantee you, if they don’t have a debrief by the first of March like they said, we’ll have a hearing and we’ll subpoena. We’re not going to wait any longer,” McCain said. “We will subpoena the individuals if we have to.”

McCain said he raised the case in a meeting on Saturday with Kerry on the sidelines of the security conference in Munich.