President Donald Trump is using his postelection public appearances to talk about the lasting physical changes he hopes to leave behind at the White House.

In the two days since Republicans suffered massive losses in the midterm elections, Trump has spoken twice in public. Both times he focused on rooms and renovations at the White House.

On Thursday, Trump signed a proclamation that designates the Oval Office and the Cabinet Room as a national monument in an effort to block any significant changes to them by future presidents.

“We’re going to be declaring it a national monument, and we’re going to send it over to Congress to have it ratified,” Trump told reporters in the Oval Office. “It won’t be able to be taken down, destroyed, touched or anything else.”

Trump, who later took questions from reporters about other topics, said any “major modifications” to the Oval Office and the Cabinet Room would have to be approved by Congress, adding that he hopes “the people in Congress will be smart enough not to let that happen.”

The White House has officially been a U.S. National Historic Landmark since 1960. Trump wrote in the proclamation that “the Oval Office merits specific recognition and protective management as a discrete historic structure of national significance.”

The signing ceremony came a day after Trump spoke to reporters at the construction site for the new White House ballroom he’s building. Even though it was his first time addressing the media publicly after the Democrats swept several seats in deep red states to secure control of Congress, he focused his comments on the ballroom.

“I’m doing it because the White House is the ultimate symbol of America and it’s got to be pristine — it’s got to be perfect,” Trump said, adding that he felt “it would be appropriate to have the media here.”