Prime Minister Keir Starmer said on Saturday that British forces and aircraft were participating in coordinated defensive efforts to protect the country's interests and allies, but were not taking part in U.S. and Israeli strikes against Iran.

The strikes targeted Iran's top leaders and plunged the Middle East into a conflict that U.S. President Donald Trump said would end a security threat to the United States and give Iranians a chance to topple their rulers.

"Our forces are active and British planes are in the sky today as part of coordinated regional defensive operations to protect our people, our interests and our allies, as Britain has done before, in line with international law," Starmer said in a video statement posted on X.

"We've stepped up protections for British bases and personnel to their highest level."

The government did not respond to a request for comment seeking details on the "defensive operations."

Starmer added that Iran must never be allowed to develop nuclear weapons and that ensuring that remains a priority for Britain and its allies.

The British prime minister reiterated that Britain had not taken part in the U.S. and Israeli strikes against Iran earlier on Saturday, but noted that "the regime in Iran is utterly abhorrent."

Starmer spoke to his French and German counterparts following a COBRA emergency meeting earlier on Saturday, as part of a series of calls with allies.

In a joint statement, the leaders condemned "Iranian attacks on countries in the region in the strongest terms" and called for a resumption of negotiations, urging the Iranian leadership to seek a negotiated solution.

The British prime minister said in his video statement that it was crucial to prevent further escalation into a wider regional conflict.

Starmer said Iran could end the conflict now.

"They should refrain from further strikes, give up their weapons programs, and cease the appalling violence and repression against the Iranian people – who deserve the right to determine their own future, in line with our longstanding position," he said.

The government earlier on Saturday issued a notice advising against all travel to Israel and the Palestinian territories, while urging citizens in Gulf states to seek shelter after moving embassy staff from Tel Aviv to another location in Israel on Friday.