Iran and U.S. Square Up in Gulf Confrontation as Congress Passes New Sanctions Against Islamic Republic

A ballistic missile is launched and tested in an undisclosed location in Iran, February. Reuters Photographer

Iran's Revolutionary Guards said Saturday that U.S. Navy vessels approached their patrol boats in the Persian Gulf in what it described as a provocation, at a time when tensions between the two countries are high, following new U.S. sanctions that have been roundly condemned by Tehran.

"At 4 pm (1130 GMT) on Friday, the supercarrier USS Nimitz and its accompanying warship, while being monitored by the Guards' frigates, flew a helicopter near the Resalat oil and gas platform and approached the force's ships," the Guards said in a statement, as quoted by AFP.

"The Americans in a provocative and unprofessional move, sent a warning message to the frigates and fired flares."

The Guards "ignored the unconventional move by the U.S. ships and continued their mission, after which the supercarrier and its warship left the area," the statement added.

This incident followed further confrontation in the Gulf when a U.S. naval vessel fired warning shots at a Guards vessel as it closed in on the American boat, U.S. officials said Tuesday. The Guards denied approaching the vessel, and said the Americans were at fault.

In an earlier incident in January, the USS Mahan destroyer fired warning shots at four Iranian Revolutionary Guard vessels that approached at high speed in the Gulf's Strait of Hormuz.

Iran condemned new sanctions against its missile program passed by U.S. Congress, and expected to be signed into law by President Donald Trump.

The move followed reports that Trump charged a team of trusted White House staffers with preparing a case that Iran was failing to uphold its side of the landmark nuclear deal negotiated by the Obama administration.

Under the terms of the deal, Iran agreed to increased inspection of its nuclear facilities in return for a range of sanctions being dropped. The U.S. must certify that Iran is meeting the conditions of the deal every three months.

The sanctions bill passed by the U.S. Senate Thursday targets six companies owned or controlled by Shahid Hemmat Industrial Group that are alleged to be central to Iran's missile program.

Russia and North Korea were also the subject of further sanctions.

Iran successfully tested a rocket that can deliver satellites into orbit on the day the sanctions were announced. The U.S. said the rocket launch violated the UN Security Council resolution that endorsed the 2015 nuclear deal, and called on Tehran not to use ballistic missiles capable of bearing nuclear warheads.

Iran pledged to forge ahead with its missile program Saturday.

"We will continue with full power," foreign ministry spokesman Bahram Ghasemi told state broadcaster IRIB.

"We consider the action by the US as hostile, reprehensible and unacceptable, and it's ultimately an effort to weaken the nuclear deal," Ghasemi added,

"The military and missile fields... are our domestic policies and others have no right to intervene or comment on them.

"We reserve the right to reciprocate and make an adequate response to the U.S. actions," he said.