The State Department refused to say whether it has demanded that Iran release a Marshall Islands cargo vessel commandeered by the Islamic Republic.
"We continue to monitor the situation. We are in touch with the Marshall Islands," said Jeff Rathke, a spokesman for the State Department, after being asked whether the United States has made any effort to retrieve the ship.
When asked again, Rathke said that he had nothing else to read out.
On Tuesday, Iranian ships forced the Maersk Tigris, a Marshall Islands cargo ship, further into Iranian waters by firing a warning shot across its bow. The cargo vessel was traveling through the Strait of Hormuz when it was confronted at 5:05 a.m. Eastern time.
The Embassy of the Marshall Islands in Washington, D.C., claimed that the United States is obligated by treaty to defend the Marshall Islands.
"The United States has the full security responsibility over the islands and for the defense of the islands, this is what our treaty says," said Junior Aini, the chargé d'affaires for the embassy.
The Pentagon has denied that a U.S. military response was obligated by treaty.
"I am not aware of any specific agreement or treaty that calls for us to protect Marshallese vessels. We do have a clear interest in protecting freedom of navigation," a Pentagon official said.
Earlier this week, the State Department refused to condemn Iran for the attack.