Former mayor of London and foreign secretary Boris Johnson has secured his party's nomination to be the next prime minister of the United Kingdom. He is expected to take office on Wednesday.

Johnson promised to get right to work

"I say to all the doubters — 'Dude, we're going to energize the country," Johnson said in his acceptance speech on Tuesday morning.

He promised to "work flat-out from now on with my team that I will build," adding "[t]he campaign is over and the work begins."

Only registered conservatives got to vote in this election

Very unlike how the president is chosen in the United States, in the United Kingdom the prime minister is chosen to represent whichever party (or coalition of parties) is in control of Parliament. All citizens vote on members of Parliament, and then only members of whichever party wins the most seats choose a prime minister.

Since the conservatives currently control parliament, they were given the task of replacing current-Prime Minister Theresa May, who resigned in May over the outcome of her attempts to pass a Brexit plan. May was also a member of the conservative party.

Unlike May, who had opposed Brexit before she was elected but promised to see it through, Johnson was a proponent of leaving the European Union from the beginning.

May congratulated her replacement on Twitter on Tuesday, saying that he has her "full support from the back benches."

Johnson was born in the US, but renounced his citizenship because of the IRS

If not for the U.S. tax code, Johnson could have been the first American citizen to become prime minister of the United Kingdom. Johnson was born in New York City (his father was a student at Columbia University at the time), although his parents left the U.S. and returned to England when he was only five-years-old. He was still an American citizen in 2015 when he sold a home in London and the IRS demanded he pay tax on it to the American government. Johnson, who was then mayor of London, paid the tax and then renounced his citizenship the following year to prevent the same thing from happening in the future.

Trump congratulated Johnson

In a tweet on Tuesday morning, President Donald Trump congratulated Johnson adding "[h]e will be great!"

Although he's a career politician, Johnson has often been compared to Trump because of his tendency to ignore decorum in favor of speaking his mind, his populist leanings, and his unruly blonde hair.