LONDON ― Britain’s defense secretary has put at least a £3 billion-a-year (U.S. $4 billion) price tag on the value of the country’s close military relationship with the US, but conceded that the arrangement was priceless to the government.

“We benefit massively from our relationship with the U.S. I said you couldn’t actually put a price on it, but when you look at [it] in terms of the benefits we get on a yearly basis I think we would benefit to the tune of a very minimum of £3 billion, and that is taking a very conservative approach,” Gavin Williamson told the parliamentary Defence Committee on Tuesday.

Williamson said the benefits came in “terms of technology, in terms of joint programs working together. Quite frankly we would always struggle to put that level of investment into a program if we wanted to bring it to fruition, so we are a massive beneficiary of this relationship.”

The remarks come as the committee concluded an inquiry into British relations with the U.S. and NATO. The findings of the report are expected to be published in the next few months.

The defense secretary earlier in the day announced the Ministry of Defence had on May 21 hosted a meeting with the U.S. Defense Innovation Board in London aimed at sharing, among other things, innovation priorities.

Britain’s relationship with the U.S. could take a serious hit, however, should media reports from last week prove true ― that London is considering cutting its pledge to buy 138 Lockheed Martin F-35 fighter jets and instead purchase more of the cheaper Eurofighter Typhoons as part of its defense review, officially known as the Defence Modernisation Programme.

One British newspaper described the possible move as “an epic snub” to Washington.

Williamson also announced Britain’s investment in the creation of what will be called the AI Lab ― a defense center for artificial intelligence, machine learning and data science based at the MoD’s Defence Science and Technology Laboratory facility in Porton Down, southwest England.

With the cash-strapped MoD expected to publish the defense review ahead of the NATO summit in Brussels scheduled for July 11, lawmakers wanted to know whether Washington had voiced an opinion about British defense spending.

Williamson said the U.S. Defense Department and others in the states had contributed to the defense review, but the subject of money hadn’t been on the agenda formally or informally.

“What they have asked is to make sure we have the right capabilities. But we have not had a discussion about defense spending. ... They have put a very high value on the capabilities we have, and they would be very concerned to see that capability eroded,” Williamson told the committee.

The defense secretary specifically noted “massive ticket items that the U.S. sees as pivotal for the defense and security of NATO members”:

  • Rapid deployment of troops as part of NATO.
  • Special forces.
  • The new Queen Elizabeth-class aircraft carrier battle group.
  • The nuclear deterrent.
  • Countering the uptick in Russian submarine activity in the North Atlantic.

Williamson also mentioned the Royal Navy’s mine-hunting capabilities and said Britain is a world leader in terms of technological development done in partnership with the U.S., asserting that in some cases the U.S. is further behind Britain.

Under the Obama administration, senior U.S. military and diplomatic figures voiced concern over Britain’s declining defense capabilities as spending slipped close to falling below the NATO-set spending target of 2 percent of gross domestic product.

“They [the U.S. administration] recognize that our commitment to 2 percent is something to be praised and is an important signal to other European nations to be spending at that same level,” Williamson said.

Earlier this month, Woody Johnson, the U.S. ambassador in London, urged Britain to increase its defense spending.

The Defence Modernisation Programme is meant to prioritize British capabilities and programs, in part to reflect the rapidly changing threat posed by Russia and others since the Strategic Defence and Security Review was published in 2015.

The MoD, which is facing a multibillion pound black hole in the defense equipment and other budgets over the next few years, will have to find significant cuts from efficiency gains and other measures to balance the books. The department is also fighting for more money from the Treasury to stave off cuts.

Defense funding problems took a new knock Tuesday when the National Audit Office, a government-spending watchdog, warned that the program to design, build and support nuclear submarines over the next 10 years faces a £6 billion funding gap.

The NAO said the nuclear submarine program, principally the building of four Dreadnought-class nuclear missile submarines, could face delays and cost overruns partly caused by a lack of nuclear engineering skills and the complexity of the project.