US President Donald Trump is demolishing the entire East Wing of the White House to build a ballroom at the property, he said on Wednesday, in a move exceeding the original scope of the project and prompting controversy over the extent of the construction.

Trump told reporters he had undertaken “really a tremendous amount of study with some of the best architects in the world” and determined that knocking down the East Wing was the best course of action. The existing structure, he said, could “hurt” his planned ballroom.

“In order to do it properly, we had to take down the existing structure,” Trump said.

Trump unveiled his ballroom plans over the summer, after long complaining about wanting a larger room for entertaining at the White House.

Originally, the president said the work on the White House grounds would not “interfere with the current building” and that the project’s plans paid “total respect” to the existing structure’s architectural style. He also pegged the total cost at around US$200 million dollars.

On Wednesday, Trump said the price had risen to US$300 million but would be paid entirely by “me and some friends”, including donors.