LONDON - The United Kingdom plans to order more F-35 Joint Strike Fighters by 2025, a top Defence Ministry official said.

Jeremy Quin, the minister for defense procurement, said the UK would be adding to the 48 jets it has already purchased from Lockheed Martin.

“By 2025, we will be placing orders—I’m absolutely confident—for more of them,” Quin said during an interview Tuesday.

But Quin declined to say whether Britain’s original plan to buy a total of 138 jets remains unchanged. The Defense Ministry’s new defense strategy is similarly mum on the question.

The U.S. Air Force is considering trimming its own purchases of the F-35A variant; its current 1,763-jet plan was laid out in 1997. Top service leaders have recently declared the F-35A the cornerstone of its future combat fleet, but some generals are calling for earlier-than-planned development of a new generation of warplanes.

The United Kingdom’s projected fleet of 138 jets is the third-largest of any nation, behind only Japan’s 147 aircraft and the United States’ tri-service fleet of more than 2,400.

Meanwhile, the UK military’s top procurement official touted work on the Tempest Future Combat Air System, a new-generation warplane under development.

The new U.K. defense strategy calls for boosting Tempest funding by nearly $3 billion. U.K. companies are also making their own investment in technology being considered for the new-generation warplanes, Quin said.

BAE Systems, Rolls-Royce, Leonardo and MBDA are among the “Team Tempest” companies working on the new warplane, which is envisioned to replace the Royal Air Force’s Eurofighter Typhoons beginning in the mid-2030s.