The post of PM in the UK
"The Honourable Elizabeth Truss MP attended an audience with the King this morning and tendered her resignation as Prime Minister and First Lord of the Exchequer, which His Majesty graciously accepted," the statement said.
Ms Truss will be replaced by Rishi Sunak when he meets King Charles III later today.
In her final speech as prime minister, Ms Truss warned that the nation continues to "struggle through the storm" but insisted that she believes "brighter days lie ahead".
Speaking from Downing Street, Ms Truss said: "Since becoming Prime Minister, I am more convinced than ever that we need to be bold and confront the challenges we face."
Ms Truss has made no apologies for the disastrous mini-budget that caused financial turmoil and led to a chaotic end to her premiership.
She continued to stick to her ideals of tax cuts despite being forced to change much of her policy when new chancellor Jeremy Hunt was brought in to clear up the mess.
She referred to one of the benefits of Brexit as "lower taxes so people keep more of the money they earn" before wishing Mr Sunak "every success for the good of our country".
Allies hope it will stabilise the party after Johnson's dramatic fall and his successor's fleeting but tumultuous tenure.
It is worth noting that Truss announced her resignation on 20 October following the failure of her economic policies and amid growing resentment from her Conservative Party colleagues. She spent a total of 49 days as prime minister, setting an anti-record. In her farewell speech as head of government, Truss cited among her main achievements the refusal to raise the social security tax and the freezing of electricity tariffs for households and businesses.
Former finance ministry chief Rishi Sunak will be the new prime minister and will meet Charles III in the next few minutes to get a mandate to form the government.