LONDON — British Prime Minister Keir Starmer called on Donald Trump to step back from military action against Iran on Thursday, warning of a “real risk of escalation” in the Middle East as he pushed instead for more talks on Iran’s nuclear program.

Starmer, who has studiously avoided splits with Trump since the U.S. president’s January return to the White House, told reporters that negotiations on Iran’s nuclear program — a major target of Israeli bombing in recent days — remained “the way to resolve this issue.”

“Obviously, all of us, U.K. included, are very concerned about the nuclear program that Iran is developing, we’ve long been concerned about that,” Starmer said.

“Also, [we] completely recognize Israel’s right to self-defense, but the principle is that we need to de-escalate this.”

He added: “There’s a real risk of escalation here that will impact the region, possibly beyond the region, akin to Gaza, and obviously it’s already having an impact on the economy.”

Starmer’s comments come after the Spectator reported that U.K. Attorney General Richard Hermer had raised legal concerns about potential British involvement in the conflict, which could involve the use of the joint U.K.-U.S. airbase on Diego Garcia, part of a British overseas territory in the Indian Ocean.

Starmer declined to comment directly on those reports, saying: “The attorney’s advice is never disclosed by any government, but I can tell you the principle — the driving intent — which is that [of] de-escalation.”

Of Iran he said: “It’s very clear: Yes, we need to deal with the nuclear program, there’s no doubt about that in my mind, but it is better dealt with as a negotiated outcome.”

He added: “De-escalate and get to that point.

“There have been several rounds of discussions with the U.S. That, to me, is the way to resolve this issue.”

Starmer’s spokesperson told reporters on Thursday that de-escalation remained the government’s “priority” regarding the conflict, and that “we would not want to see anything that ramps up the situation.”

Asked if the U.K. could block the U.S. from using Diego Garcia to strike Iran, the spokesperson declined to discuss hypotethicals or “speculate on future operations.”

British Foreign Secretary David Lammy will discuss the crisis on Thursday night with U.S. Secretary of State Marco Rubio on a trip to Washington.

The BBC reported Thursday that dozens of U.S. military jets rarely seen outside the country had landed at RAF Lakenheath in Suffolk, England Wednesday night. The broadcaster cited a U.S. defense official who declined to provide details on the deployment due to “operational security.”