London Mayor Boris Johnson will refuse to pay U.S. tax, defying American demands on him as a dual citizen.

“The United States comes after me, would you believe it, for the, for capital-gains tax on the sale of your first residence, which is not taxable in Britain, but they’re trying to hit me with some bill, can you believe it?” Johnson said on National Public Radio in New York in an interview first aired last week.

Asked if he would pay it, he said: “Well, I’m -- no, is the answer.”

Johnson, the mayor of London since 2008 and a potential candidate to lead Prime Minister David Cameron’s Conservative Party, was born in New York City in 1964. He lived in the U.S. for much of the first five years of his life and often praises the country of his birth.

Johnson said that tax on his earnings, which include the mayor’s salary of 144,000 pounds ($226,000), is paid “to the full in the United Kingdom, where I work and live.”

The rules for U.S. citizens are “generally the same” whether they live in America or abroad, and citizens’ worldwide income is subject to tax, according to the website of the Internal Revenue Service, which is responsible for collecting tax.