Liz Truss has been formally appointed the UK's new prime minister after meeting the Queen at Balmoral Castle, Scotland.
Truss, 47, is the fourth British prime minister in a little over six years, and takes over at a delicate time for the country, with soaring costs of living exacerbated by rampant gas prices caused by the Russian invasion of Ukraine.
It comes after members of the ruling Conservatives yesterday chose her to succeed the scandal-hit Boris Johnson as party leader.
Buckingham Palace said in a statement that during the audience the Queen had "requested [Truss] to form a new administration”.
"Ms Truss accepted Her Majesty's offer and kissed hands upon her appointment as Prime Minister and First Lord of the Treasury", the palace added.
After Queen Elizabeth II formally asked Truss to form a new government on Tuesday, part of a carefully choreographed ceremony dictated by centuries of tradition, she must now appoint her cabinet, which will signal whether she intends to surround herself with allies or will look to mend bridges after a fractious campaign to replace Johnson.
Truss declined to lay out her energy strategy during the two-month campaign to succeed Johnson. But she is expected to announce plans to cap energy bills at a cost to taxpayers of as much as £100 billion (€116 billion), according to British media reports. The plan is expected to be unveiled on Thursday.
As Conservative Party leader, Truss automatically became prime minister without the need for a general election, since the party has a majority in the House of Commons.
However, as a prime minister selected by fewer than 0.5% of British adults, she is under pressure to show quick results.
Ed Davey, leader of the opposition Liberal Democrats, has already called for an early election in October.
Truss left Balmoral Castle at around 1 pm local time to head back to London to begin her premiership.