British forces played a role on Tuesday in preventing further escalation fuelled by Iran's missile attack, the defence secretary said after Prime Minister Keir Starmer assured Israel of his "steadfast commitment" to the country's security.
Iran fired a salvo of ballistic missiles at Israel in retaliation for Israel's campaign against Tehran's Hezbollah allies in Lebanon, and Israel vowed a "painful response" against its enemy.
Asked whether Britain was prepared to use its military to help Israel defend itself, Starmer said Israel has the right to self-defence and "any relevant updates will be provided in due course".
Later on Tuesday, Defence Secretary John Healey said in a statement on X that "British forces have this evening played their part in attempts to prevent further escalation in the Middle East," and he thanked the personnel involved for their courage and professionalism.
He did not elaborate. The ministry of defence did not immediately reply to a Reuters request for comment on how British forces were involved.
In Washington, President Joe Biden said the United States was prepared to help Israel defend itself.
Starmer spoke with Israel's Benjamin Netanyahu on Tuesday afternoon, and the leaders discussed the escalating situation across the Middle East, a spokesperson for the British premier's office said.
Starmer condemned Iran's attack on Israel, which began during the leaders' conversation, in the "strongest terms", the spokesperson added.
"It cannot be tolerated," Starmer told reporters. "We stand with Israel and we recognise her right to self defence in the face of this aggression. Iran must stop these attacks."
Alarms sounded across Israel and explosions could be heard in Jerusalem and the Jordan River valley, and Israelis piled into bomb shelters.
Starmer spoke with Jordan's King Abdullah, and they underscored the urgent need for a ceasefire in both Lebanon and Gaza, Starmer's office said.
Starmer said he also held calls with French President Emmanuel Macron and German Chancellor Olaf Scholz to "try to find the space for a political solution".
The leaders acknowledged the serious risk of regional escalation and agreed all sides should show restraint.
On X, British Foreign Minister David Lammy said he "warned Iran against taking action that could push the region further towards the brink".
"A cycle of escalation is in no one's interest," Lammy said.