Boris Johnson, the U.K.'s former foreign secretary and a fierce backer of Brexit, will replace Theresa May as prime minister after winning the Conservative Party's leadership contest on Tuesday.
Johnson, who has been one of the most vocal proponents of the country's planned withdrawal from the European Union, received 92,153 party votes to defeat Jeremy Hunt, who received 42,656.
"I give notice that Boris Johnson is elected as the leader of the Conservative and Unionist parties," Parliament member Cheryl Gillian announced.
President Trump quickly congratulated Johnson.
"Congratulations to Boris Johnson on becoming the new Prime Minister of the United Kingdom," Trump tweeted. "He will be great!"
Following the announcement, Johnson pledged to complete Brexit.
"I say to all the doubters, dude, we are going to energize the country. We're going to get Brexit done."
"We are going to unite this amazing country and we are going to take it forward," he added.
The politician also said that he favored better education, better infrastructure, more police and broadband in every household.
The contest follows May's resignation after she was not able to come up with a Brexit plan that could gain Parliament's support.