The United States is discussing with its allies a variety of options on how to protect international shipping in the Gulf of Oman in the wake of tanker attacks that Washington has blamed on Iran, senior Trump administration officials said on Thursday.

Two officials, speaking to a small group of reporters on condition of anonymity, said the United States wants to ensure the freedom of navigation in the Strait of Hormuz and make sure international commerce is not disrupted.

Two oil tankers were attacked on Thursday and left adrift in the Gulf of Oman.

"We don't think this is over," one official said of the possibility of more such attacks.

The official said options are being reviewed.

"We're discussing and will be discussing with our partners and allies suggestions on how we collectively can take steps to ensure, one, that we maintain freedom of navigation and international commerce is not disrupted and, second, that we protect our forces' interests and our commercial assets and those of our partners and allies," the official said.

The official said the attacks appeared "designed to have a political outcome" and suggested it could have been an attempt to disrupt a visit to Tehran by Japanese Prime Minister Shinzo Abe.

"We are going to obviously evaluate our presence in the region and the growing threat and make subsequent decisions," the official said. "We have to look at the threat, as we always do, to our personnel and our forces but the threat to a strategic chokepoint. There's a significant amount of trade that transits the Strait of Hormuz every day."