LONDON, Britain on Monday joined the United States in a maritime security mission in the Gulf to protect merchant vessels travelling through the Strait of Hormuz after Iran seized a British-flagged vessel.

British officials stressed that there was no change to London's policy on Iran but joining the United States is the most significant non-Brexit foreign policy move to date of Prime Minister Boris Johnson's 12-day-old government, Reuters reported on Monday. No other nations are yet involved in the US mission.

"It is vital to secure the freedom for all international shipping to navigate the Strait of Hormuz without delay, given the increased threat," said British Defence Secretary Ben Wallace.

"The deployment of Royal Navy assets is a sign of our commitment to our UK flagged vessels and we look forward to working alongside the US and others to find an international solution to the problems in the Strait of Hormuz," he said.

Tanker traffic through the Strait - through which a fifth of the world's oil passes - has become the focus for a standoff between Iran and the United States, which has beefed up its military presence in the Gulf since May.

Last month, Iran's Revolutionary Guards seized a British tanker, Stena Impero, near the Strait of Hormuz for alleged marine violations. That came two weeks after Britain seized an Iranian oil tanker near Gibraltar, accusing it of violating sanctions on Syria. Britain has repeatedly ruled out any exchange.

"Our approach to Iran hasn't changed," British Foreign Secretary Dominic Raab said. "We remain committed to working with Iran and our international partners to de-escalate the situation and maintain the nuclear deal," he said.

Britain has deployed a destroyer HMS Duncan and a frigate HMS Montrose to the Gulf to accompany UK-flagged vessels through the strait. So far, 47 ships have been accompanied by the naval vessels, British officials said.

Later this year, another Type 23 Frigate, HMS Kent, will take over from HMS Duncan, while HMS Montrose completes planned maintenance. HMS Montrose will remain stationed in the Middle East until 2022, said the Reuters report.

Source: Emirates News Agency