LONDON (AP) -- Andy Burnham, the former mayor of Greater Manchester and new leader of the Labour Party, took the final steps on Monday to succeed Keir Starmer and become Britain’s seventh prime minister in a decade. It was one of Burnham's first phone calls since he entered No.10 Downing Street, the residence of the UK prime minister. Burnham, who has little foreign policy experience, has said that Britain will remain a firm United States ally. Burnham's predecessor, Keir Starmer, who stood down earlier, was a high-profile supporter of Ukraine in its war with Russia. Burnham, who has very little foreign policy experience, has said he will continue to provide Ukraine with the support it needs.