LONDON — British officials are working to negotiate down Donald Trump’s 10 percent tariffs on British exports, Peter Mandelson, the U.K.’s ambassador to Washington, said Tuesday.

Earlier this month Prime Minister Keir Starmer became the first world leader to reach a deal with Trump to lower the White House’s 25 percent tariffs on car, steel and aluminum imports into the U.S.

Yet the deal failed to lower the 10 percent baseline tariffs Trump announced in April.

“We need to address [the reciprocal tariffs] and we’re agreed to do so,” Mandelson told an Atlantic Council event.

Washington and London “can build on” the deal that they’ve agreed, Mandelson said, using it to open the door to a technology partnership between the two countries.

In negotiating down Trump’s 10 percent baseline tariffs the two sides are looking at non-tariff barriers, Mandelson said.

“I think this is a source of irritation to the president,” he added. As a former EU trade commissioner, “I can understand his frustration.”

Trade Secretary Jonathan Reynolds insisted when the deal was unveiled that Britain’s digital services tax had not been touched in the talks. But it was not immediately clear that it would remain untouched in future talks.

“Everything’s on the table,” said one U.K. official when asked about digital services tax. “If it’s something fantastically attractive … if the sum that goes into the deal outweighs what goes with the digital services tax, then let’s do it.”

British businesses are still awaiting clarity on when the steel, aluminum and auto tariffs will be lifted.