Liz Truss has become Britain's 56th prime minister and will soon deliver her first address to the nation after an audience with the Queen.
It comes 24 hours after the former foreign secretary emerged victorious in the Tory leadership contest - beating rival Rishi Sunak to replace Boris Johnson in No10.
Earlier on Tuesday Mr Johnson left Downing Street for the last time as prime minister, using his last speech to urge Tory MPs to unite behind his successor.
Just moments after he formally offered his resignation to the Queen, Ms Truss was invited to form a government at a meeting with the monarch in Balmoral, Scotland.
In a statement, Buckingham Palace said: "The Queen received in audience the right honourable Elizabeth Truss MP today and requested her 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."
She arrived at the Aberdeenshire estate by car shortly after 12.20pm for her meeting with her husband, Hugh O'Leary.
After the meeting, the new PM's team swiftly updated her Twitter profile to mark her new role
"Prime Minister of the United Kingdom of Great Britain and Northern Ireland. Leader of the Conservative Party. MP for South West Norfolk," the description states.
She will now begin the journey back to Downing Street and deliver her first address to the nation as prime minister at around 4pm.
Within days of entering No 10, Ms Truss is expected to announce a package of measures to help struggling families with surging energy bills after weeks of dodging questions on the issue.
She is also expected to present an emergency budget in the coming weeks, after making tax cuts a cornerstone of her campaign for the Tory leadership.
In his Downing Street speech, Mr Johnson said Russian President Vladimir Putin is "utterly deluded" if he thinks he can succeed by "blackmailing and bullying" the British public through restricting gas supplies, driving up world prices.
"We have and will continue to have that economic strength to give people the cash they need to get through this energy crisis that has been caused by Putin's vicious war," he said.
"I know that Liz Truss and this compassionate Conservative government will do everything we can to get people through this crisis, and this country will endure it and we will win."
This breaking news story is being updated
