United Kingdom (UK) Prime Minister Liz Truss makes a statement outside 10 Downing Street in London, Britain, Oct. 20, 2022.(Xinhua/Li Ying)

United Kingdom (UK) Prime Minister Liz Truss resigned on Thursday after just a little over six weeks in office and thus became the shortest-serving prime minister in the country's history.

In a statement outside 10 Downing Street, she said that there will be a leadership election "to be completed within the next week" and that she will remain as caretaker prime minister until a successor has been chosen.

"I came into office at a time of great economic and international instability," she said. "Our country has been held back for too long by low economic growth. I was elected by the Conservative Party with a mandate to change this ... I recognize though, given the situation, I cannot deliver the mandate on which I was elected by the Conservative Party."

Truss's resignation came after the mini-budget, the fiscal plan announced by her government last month, caused economic chaos and tanked the ruling Conservative Party's poll rating.

The mini-budget, which contained controversial debt-funded tax cuts, has been blamed for plunging the British pound to a 37-year low against the U.S. dollar, while pushing up the cost of government borrowing and mortgage rates.

One of the main architects of the fiscal plan, Kwasi Kwarteng, left his post as chancellor of the exchequer last week. His successor, Jeremy Hunt, tore up almost all the announced tax cuts and limited the government's cap on rising energy prices.

With her economic strategy reversed and Kwarteng gone, Truss's premiership had been considered untenable. On Wednesday, Home Secretary Suella Braverman resigned, noting "serious concerns" about the direction of Truss's government.

The number of Tory lawmakers who publicly demanded Truss's resignation quickly snowballed to more than a dozen on Thursday morning. Shortly before her resignation, Truss met with Graham Brady, chair of the Tory backbench 1922 Committee, which oversees the election of Conservative leaders.

The leaders of the three largest opposition parties -- Keir Starmer of the Labour Party, Ed Davey of the Liberal Democrats and Nicola Sturgeon of the Scottish National Party -- have all called for an immediate general election.