The United States says the crew of an Iranian supertanker whose departure from Gibraltar Washington apparently was unable to block could be subject to a U.S. visa ban.
State Department spokeswoman Morgan Ortagus on August 15 said the Grace 1 was assisting Iran's Islamic Revolutionary Guards Corps (IRGC), which Washington deems a terrorist organization.
This could result in serious consequences for any individuals associated with the Grace 1, Ortagus said.
She added that members of the crew "may be ineligible for visas or admission to the United States under the terrorism-related inadmissibility grounds."
The United States will continue to use all the tools at its disposal to deny Iran and its proxies the resources they need to engage in malign and destabilizing activities in Syria and elsewhere. This includes the full enforcement of U.S. sanctions with respect to Iran and the IRGC, her statement said.
Earlier reports said the Grace 1 carried 28 personnel, mainly Indian, Pakistani, and Ukrainian nationals.
The comments came after Gibraltar said it had decided to free the supertanker that had been detained off the British overseas territory six weeks ago by Royal Marines, despite a last-minute attempt by the United States to seize the vessel.
The Grace 1 was detained on suspicion it was smuggling oil to Syria in breach of European Union sanctions.
Gibraltar Chief Minister Fabian Picardo on August 15 lifted the detention order after formal written assurances from Tehran that the ship will not discharge its more than 2 million barrels of oil in Syria.
"In light of the assurances we have received, there are no longer any reasonable grounds for the continued legal detention of the Grace 1 in order to ensure compliance with the EU Sanctions Regulation," Picardo said.
After the decision by the Gibraltar authorities, Britain's Foreign Office warned Iran to abide by the assurances it had given that led to the release of the supertanker.
It said Britain would not allow Tehran or anyone else to bypass European Union sanctions meant to punish Syria for using chemical weapons against its own people.
It was not immediately clear when the Grace 1 would sail or if it had already departed Gibraltar territorial waters.
The decision to release the tanker came despite an attempt by Washington to seize the tanker.
"That is a matter for our independent Mutual Legal Assistance authorities, who will make an objective, legal determination of that request for separate proceedings," said Picardo, who suggested it was still possible for the vessel to be seized again before it left Gibraltar's territorial waters.
Iran's foreign minister accused Washington of attempted piracy in trying to prevent the release of the oil tanker.
"The U.S. attempted to abuse the legal system to steal our property on the high seas," Mohammad Javad Zarif tweeted. "This piracy attempt is indicative of [U.S. President Donald] Trump admin's contempt for the law."
On July 19, two weeks after the seizure of the Grace 1, Iran's IRGC seized the British-flagged Stena Impero in the Persian Gulf.
Both London and Tehran have denied planning to swap the vessels.
Britain's Foreign Office said there should be "no comparison or linkage" between the enforcement of sanctions and "Iran's unacceptable and illegal seizure of, and attacks on, commercial shipping vessels in the Strait of Hormuz."
The spat between Tehran and London came amid rising tensions in the Gulf after the United States last year withdrew from the 2015 deal between world powers and Tehran.
Washington has appealed to its partners to help create a maritime security mission to help safeguard shipping and other interests in the Gulf.
Copyright (c) 2015. RFE/RL, Inc. Reprinted with the permission of Radio Free Europe/Radio Liberty, 1201 Connecticut Ave NW, Ste 400, Washington DC 20036.