Construction crews began demolishing part of the East Wing of the White House on Monday as part of President Donald Trump’s plan to build a new ballroom.

Trump previously said the project would not interfere with the existing structure, describing it as “near it, but not touching it.”

Despite that assurance, parts of the East Wing are being removed to make room for the new addition.

The ballroom construction started last month, and Trump referenced the ongoing work during a White House event this week.

He later posted that the East Wing would be “fully modernized” and that the ballroom would be “completely separate from the White House itself.”

The East Wing, traditionally used by the first lady and her staff, has been cleared out ahead of the demolition.

Trump said the ballroom will hold up to 900 guests, up from the original plan for 650, and will cost about $250 million—an increase from the initial $200 million estimate.

He said he will help fund the project personally, with assistance from private donors, including Comcast Corp, NBC News has reported.

The project marks the most significant alteration to the White House since major renovations in the 1940s.