President Donald Trump has made his plans for the White House’s physical appearance a central theme of his first public remarks since Republicans suffered major midterm election losses. In both appearances during the two days after the vote, he concentrated on renovations and the rooms he hopes to preserve beyond his presidency.

On Thursday, Trump signed a proclamation designating the Oval Office and Cabinet Room as a national monument, seeking to prevent future presidents from making significant alterations. He told reporters gathered in the Oval Office that the designation would go to Congress for ratification and said congressional approval would be required for major modifications to either room.

The White House has held National Historic Landmark status since 1960. In the proclamation, Trump argued that the Oval Office warranted its own recognition and protection as a historic structure of national importance. The document would still allow future presidents to redecorate, choose furnishings and make routine changes for operations or security, provided those changes did not substantially damage the protected structure or its architectural character.

The ceremony followed Trump’s appearance a day earlier at the construction site of his new White House ballroom. That was his first public exchange with the media after Democrats won several seats in deeply Republican states and secured control of Congress. His remarks nevertheless centered on the building project and his desire to keep the White House in pristine condition.

Construction of the ballroom required demolition of the historic East Wing, drawing criticism from preservation groups. Cosmetic changes to the Oval Office, by contrast, are common when a new administration arrives. Trump extensively redecorated the room after returning to office last year, adding abundant gold accents associated with his preferred style.

Trump later answered questions on other subjects during Thursday’s appearance. While discussing the proclamation, he highlighted what he described as his Oval Office victories, but also acknowledged, without elaborating, that there had been mistakes. Asked what Congress should prioritize during the remaining two months of Republican control, he praised his own record over the past two years, pointing to his efforts concerning the border and stock market.

Renovations also featured prominently in Trump’s final campaign speech on Monday at the Lincoln Memorial Reflecting Pool. The pool has been closed since July following renovations described as botched after he requested upgrades. Trump devoted most of those remarks to promoting its reopening and other renovation projects around Washington.