Ambassador Robert Tuttle announced Thursday that he has a provisional agreement with a developer to relocate the embassy on a 5-acre site, The Independent reported. The deal would need approval from Congress.

Tuttle said the congestion charges imposed on cars driving into central London were not a motive for the proposed move. The embassy reportedly owes the city almost $4 million.

Founding father John Adams opened the first U.S. mission in London on Grosvenor Square in 1785. During World War II, Londoners nicknamed the square Eisenhower Platz because General Dwight Eisenhower's headquarters was there.

The current embassy, designed by Eero Saarinen, dates to 1960. But upgraded security in recent years has annoyed many local residents and visitors.

"If we all still wore hats, as we did in the 1930s, we would be throwing them into the air," Peter Wetherell, a real estate agent, told The Times of London.