Brexit hard-liner Boris Johnson, one of Britain's most famous and divisive politicians, won the race to lead the governing Conservative Party on Tuesday, and will become the next prime minister in a little over 24 hours.
Then he will have just over three months to make good on his promise to lead the country out of the European Union.
Johnson resoundingly defeated rival Jeremy Hunt in the Conservative leadership contest, winning two-thirds of the votes in a ballot of about 160,000 party members across the U.K. He will be installed as prime minister Wednesday in a formal handover from Theresa May.
In a brief speech to hundreds of party members and lawmakers gathered for the announcement, Johnson radiated optimism, pledging to "deliver Brexit, unite the country, and defeat Jeremy Corbyn," leader of the opposition Labour Party.
"I think we know that we can do it, and that the people of this country are trusting in us to do it, and we know that we will do it," said Johnson, a former London mayor and foreign secretary.
"I say to all the doubters: Dude, we are going to energize the country, we are going to get Brexit done."
U.S. President Donald Trump, who has praised Johnson in the past, tweeted his congratulations and said he will be "great."
Trump has been very critical of May's inability to achieve a Brexit deal and has said Johnson will do a better job.
Hunt, who trailed in the polls throughout the contest, said he was sure Johnson would "do a great job."
"He's got optimism, enthusiasm, he puts a smile on people's face, and he has total, unshakable confidence in our amazing country," said Hunt, who is likely to be removed as foreign secretary by the new prime minister.
May stepped down after Parliament repeatedly rejected the withdrawal agreement she struck with the 28-nation bloc.
Famed for his bravado, quips in Latin and blond mop of hair, Johnson wooed Conservatives by promising to succeed where May failed and lead the U.K. out of the EU on the scheduled date of Oct. 31 -- with or without a divorce deal.
Johnson insists he can get the EU to renegotiate -- something the bloc insists it won't do. If not, he says Britain must leave the EU by the deadline, "come what may."
Economists warn that a no-deal Brexit would disrupt trade and plunge the U.K. into recession. Fears that Britain is inching closer to crashing out of the bloc weighed on the pound once again Tuesday. The currency was down another 0.3 percent at $1.2450, nearly a two-year low.
Carolyn Fairbairn, director of the Confederation of British Industry, said businesses needed a withdrawal agreement with the EU to restore confidence that has been badly shaken by uncertainty about the terms of Brexit.
"On Brexit, the new prime minister must not underestimate the benefits of a good deal," she said.
The EU is adamant that the deal it struck with May will not be renegotiated.
Michel Barnier, the EU's chief Brexit negotiator, said he looked forward "to working constructively" with the new Conservative leader "to facilitate the ratification of the Withdrawal Agreement."
British lawmakers are due to start a six-week summer break on Friday. When they come back in September, Johnson looks set for a fight with Parliament over his plans.
He will preside over a House of Commons in which most members oppose leaving the EU without a deal, and where the Conservative Party lacks an overall majority.
Education Minister Anne Milton and International Development Secretary Rory Stewart on Tuesday became the latest ministers to announce they were quitting before they could be shuffled or demoted by Johnson.
They and others plan to resist any push for a no-deal Brexit.
"We'll have to see what Boris can muster," said Margot James, who quit last week as digital minister but remains a Conservative lawmaker. She said she doubted Johnson would be able to get a new Brexit deal by the deadline.
"The default position is leaving without a deal, and there is a significant majority in Parliament who will work very hard to sure that doesn't happen. And I will be among that number."
Associated Press writer Raf Casert in Brussels contributed.
--The Associated Press