The British government has said its navy will accompany British-flagged vessels through the Strait of Hormuz to defend freedom of navigation, after previously saying it did not have the military resources to do so.
Tensions have spiked between Iran and Britain since Iran last Friday seized a British-flagged tanker in the Strait. Its move came after British forces captured an Iranian oil tanker near Gibraltar, which Britain said was heading for Syria in defiance of EU sanctions.
The British government has previously advised British-flagged vessels not to pass through the Strait of Hormuz and to notify the navy if they plan to do so.
"The Royal Navy has been tasked to accompany British-flagged ships through the Strait of Hormuz, either individually or in groups, should sufficient notice be given of their passage," a British government spokesman said.
"Freedom of navigation is crucial for the global trading system and world economy, and we will do all we can to defend it," he added in a statement.
Britain has been seeking to put together a European-led maritime protection mission to ensure safe shipping through the Strait of Hormuz after Iran's seizure of the tanker in what London said was an act of "state piracy".
France, Italy and Denmark support the idea, three EU diplomats said on Tuesday, but Germany has said it is too early to discuss how Berlin might take part.
Iran has also vowed to secure the strait and said it will not allow any disturbance in shipping there, state news agency quoted Deputy Foreign Minister Abbas Araghchi as saying on Tuesday.