The UK has agreed to allow the US to use British bases to launch strikes on Iranian sites targeting the Strait of Hormuz, according to Downing Street.
Prime Minister Sir Keir Starmer previously allowed US forces to use the bases only for defensive operations to prevent Iran firing missiles that put British interests or lives at risk.
The expansion of targets is intended to help protect ships in the vital oil shipping channel, still on the basis of collective self-defence, Downing Street said on Friday.
Reaction from World Leaders
US President Donald Trump said the UK should have acted a lot faster, while Iran's Foreign Minister Abbas Araghchi claimed Sir Keir was putting British lives in danger.
Iran fired two ballistic missiles at Diego Garcia, but neither hit the joint US-UK base on the Chagos Islands, in the Indian Ocean, according to the Wall Street Journal and CNN.
UK Involvement and Response
The UK will still not be directly involved in the US strikes, and Downing Street said the principles behind the UK's approach to the conflict remain the same.
Conservative Party leader Kemi Badenoch called the decision the mother of all U-turns, while Liberal Democrat foreign affairs spokesman Calum Miller said the government's decision showed the UK was being drawn further and further down Trump's slippery slope.
International Implications
UK military planners have joined the US Central Command to look at options for getting tankers through the strait, which has been effectively closed by the threat of Iranian attacks in retaliation to a bombing campaign by the US and Israel.
Just under 100 ships have passed through the strait since the start of March, according to data analysed by BBC Verify.
Official Statements
A Downing Street spokesperson said ministers agreed that Iran's reckless strikes risked pushing the region further into crisis and worsening the economic impact being felt in the UK and around the world.
The Foreign Office said UK Foreign Secretary Yvette Cooper had condemned Iran's reckless attacks and its disruption and closure of the Strait of Hormuz.
