The U.S. Embassy says the new building cost $1 billion, funded entirely through the sale of other U.S. properties in London.
A Trump visit has been on the cards since British Prime Minister Theresa May visited the United States a few days after Trump's inauguration past year. "Bad deal. Wanted me to cut ribbon - NO!"
British Foreign Secretary Boris Johnson said opponents such as Khan were putting the relationship with the United States, the biggest investor in Britain, at risk.
The main reason cited was security: US officials said it would have taken several years and hundreds of millions of dollars to bring the old embassy, completed in 1960, up to standard.
But Trump said his decision, announced in a late-night tweet, was due to the president's concerns about the embassy's move from the tony Mayfair district to a far less fashionable area of London.
In Washington, White House spokeswoman Sarah Huckabee Sanders said Trump's comment was exclusively about an embassy-related visit.
In a BBC interview on Sunday, May insisted that Trump "will be coming to this country" in spite of the opposition.
More than a year into his presidency, Trump has yet to visit London, with many Britons vowing to protest against a man they see as crude, volatile and opposed to their values on a range of issues.
"It seems he's finally got that message".
He took to Twitter to explain why he called off the visit, which had sparked fears of mass protests and would have been his first to the United Kingdom as President.
Image London's Mayor sat down and flicked through a paper when his speech was disrupted
A spokesman for May's Downing Street office said the invitation for the state visit "has been extended and accepted".
"We will not allow US-UK relations to be endangered by some puffed-up, pompous popinjay in City Hall", Johnson tweeted.
"No date was confirmed for any visit, the one you are referring to now".
"The US is one of our oldest and most valued allies and our strong and deep partnership will endure", the spokesman said. Last month, Ambassador Woody Johnson, who was appointed by Trump, called it a "bargain".
There had always been security concerns about the Grosvenor Square site, dating back to the late 1990s after attacks on U.S. embassies in Africa.
The new embassy is certainly in a less-central and less-prestigious location in London.
The area became known as "Little America" at the time. It will be open for business on January 16.
"A multi-disciplinary team of professionals considered over 170 criteria, to include physical security requirements, and determined that the Nine Elms site was the best overall location for the U.S. government", the statement added.
Bemused construction workers and passers-by took selfies with the Trump waxwork, which was first unveiled at Madame Tussauds in January a year ago.
There was an outburst on social media after the visit was announced past year, when protesters vowed to turn out in great numbers to let the US President know that he was not welcome in the UK.
What To Know About The Flu Virus As Season Ramps Up
It's no secret by now that the flu vaccine is not a good match with the H3N2 flu strain that is dominating the season. Flu symptoms can include fever , cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue.