Boris Johnson is planning to present Barack Obama with a congestion charge bill for £5.5m when the President visits London next week.
The London Mayor said he would use the visit to again press his argument that American diplomatic cars should be liable for the £10 charge.
The American State Department has claimed the congestion charge is an illegal tax under the Vienna convention and instructed its diplomatic, administrative and technical staff not to pay it.
"I will remind him that the US owes us £5.5m in congestion charges," Mr Johnson told BBC London. "When President Obama's hors d'oeuvre plate is whisked away, he will find a bill for £5.5m."
Mr Johnson's predecessor Ken Livingstone began London's campaign against the American and other embassies in the capital which are refusing to pay the charge, claiming it is a local tax.
"It is not a tax," said Mr Johnson. "It is a charge for services and I think we should test this in the courts. The only way we could do this is if the Foreign Office actually takes the American government to court."Reuse content