"Secretary Kerry spoke by telephone today with newly appointed UK Foreign Secretary Boris Johnson to offer his congratulations. The Secretary and Foreign Secretary Johnson agreed that the U.S.-UK special relationship is as essential as ever, and they pledged to work closely together as NATO allies to address the full range of challenges we face and to meet our responsibilities around the world," John Kirby said in a statement.
According to Kirby, Kerry and Johnson are expected to hold a meeting in Brussels next week.
Johnson, former mayor of London and a key figure in the campaign for the United Kingdom to leave the European Union, was appointed the new UK foreign secretary on Wednesday.
On Wednesday, Theresa May, having served as home secretary for the past six years, became the United Kingdom’s new prime minister, following David Cameron’s official resignation.