UK Foreign Secretary Boris Johnson relinquished his US citizenship last year, according to the United States Treasury Department's latest quarterly list released on Wednesday.

In 2015, the 52-year-old said he planned to give up his dual nationality for nationalistic reasons. He added his US passport was "an accident of birth" and that he had to "find a way of sorting it out" with then US ambassador Matthew Barzun.

"The reason I'm thinking I probably will want to make a change is that my commitment is, and always has been, to Britain," Johnson told the Sunday Times newspaper. "They (the Americans) don't make it easy for you.”

Britain's foreign ministry said London's former mayor renounced his US citizenship in early 2016, after which it took some time to be processed by the American system.

A shortened version of Johnson's full name, Alexander Boris de Pfeffel Johnson, appeared on the US Treasury Department list of 5,411 people who gave up their American citizenship in 2016.

After selling his house in north London in 2015, Johnson settled a capital gains tax bill sent by the United States. The minister called the tax requirement "absolutely outrageous," as he had not lived in the country since he was 5 years old. The United States is one of the only countries to tax citizens who live overseas on their worldwide income.

The flamboyant political figure was appointed foreign secretary last July, shortly after Britain voted to leave the European Union.

Although Johnson accused Donald Trump of "being out of his mind” at the beginning of his presidential campaign in 2015,the foreign secretary quickly adjusted his outlook after President's Trump's election late last year, saying "there's a lot to be positive about.”

mem/rt (AFP, AP, dpa)