The United States embassy in London has racked up over $10 million in congestion fee fines, topping the list of embassies that owe the government for the luxury of driving in the busy British capital.

British Foreign Secretary William Hague, who announced the new figures in parliament on Thursday, repeated requests that nations please pay their dues. Russia was the second-largest offender, followed by Japan.

The London congestion fee was introduced in 2003, to reduce traffic in the overcrowded city.

Foreign embassies in the British capital commonly dispute the charges. The United States claims diplomatic immunity exempts its diplomats from having to pay, but a British Foreign Office spokeswoman told the BBC on Thursday that the government considers the fees a "service rendered."

Even so, the UK cannot take diplomats to court if they don't pay.

This isn't the first time the long-running issue has put a wrinkle in US-UK relations.

Two years ago, as US President Barack Obama was preparing to visit London, Mayor Boris Johnson warned: "Maybe when President Obama's hors d'oeuvre plate is whisked away, he will find a bill."

The US ambassador reportedly intervened in the hors d'oeuvre affair, but the US continued to rack up fines. When Obama nominated a new ambassador for the UK, Johnson reportedly said, “I do hope he’ll put those skills to good use in finding the more than £6 million ($9 million) owed by US diplomats to Londoners in unpaid C[ongestion]-charge fines."

As if the congestion fines weren't enough, Hague also said Thursday that diplomats owed more than $500,000 in London parking fees in 2012.