President Trump on Thursday signed a proclamation that he says will preserve the Oval Office and Cabinet Room as a national monument, his first official action after his party was swept aside in midterm elections on Tuesday.
But the action does not prevent future presidents from restyling the iconic office that Mr. Trump has filled to the brim with gold flourishes, nor does it prevent a successor from rolling back the proclamation itself. Mr. Trump himself has reversed national monument designations made by his predecessors.
Mr. Trump, however, described the Oval Office order in expansive terms.
“It will not be allowed to be touched by anybody, destroyed, ripped down by stupid people, in order to build something in a slightly different shape,” Mr. Trump said. “We like the Oval Office, and it’s a symbol, like the White House itself.”
Jim Lo Scalzo / EPA / Bloomberg via Getty Images 
It was the third day this week that the president, a real estate mogul, delivered remarks fixated on his pet projects in Washington. On Wednesday, a day after Republicans suffered defeats in key races across the country, Mr. Trump gathered reporters to see the final beam being raised during construction of his opulent ballroom project. On Monday, he went to the Lincoln Memorial Reflecting Pool to talk about his renovation of the landmark.
The proclamation, released after Mr. Trump’s remarks, says that nothing in it will “restrict the President’s authority to redecorate the monument, select furnishings, or make ordinary operational and security modifications that do not substantially impair the monument’s historic structure or architectural character.”
It orders the Interior secretary to manage the Oval Office and requires “documentation, review, and consideration of alternatives before any action that would substantially alter or demolish the monument.” Mr. Trump separately said any major changes would need review from Congress, though such a requirement is not in the document’s text.
“If they want to say, ‘Let’s not have oval anymore, let’s make it square,’ what happens is they have to go back to Congress and hopefully the Congress, the people in Congress, will be smart enough not to let that happen,” said Mr. Trump — who notably demolished the East Wing of the White House to make room for his ballroom.
A red baseball cap with “VETO” on the front was sitting on the Resolute Desk as Mr. Trump signed the document, a not-so-subtle nod to the shifting of powers in Congress.
His effort to preserve changes at the White House comes as Democrats gear up for new scrutiny of Mr. Trump. Connecticut Sen. Richard Blumenthal, the top Democrat on the Homeland Security Committee’s Permanent Subcommittee on Investigations, sent a flurry of letters Thursday to known donors to Mr. Trump’s ballroom, demanding that they provide information or face “alternative measures to obtain compliance.”
Since returning to the White House, Mr. Trump has overseen numerous design changes to various rooms, including the Oval Office, where he has filled the wall space with portraits, a copy of the Declaration of Independence and numerous golden accents.
As he talked about his interior decorating decisions, Mr. Trump highlighted new chandeliers that he says were installed in the Cabinet Room to address “very bad lighting.” His other additions to the Oval Office include numerous gold wall appliqués and gold-framed portraits.
Mr. Trump did not elaborate on precisely what he was hoping to prevent but suggested that the Oval Office might face some threat in the future. Mr. Trump himself has faced several lawsuits alleging that his Washington beautification projects were done without the necessary approval.
“If anybody ever decides to come and start knocking down walls, you call me wherever I may be,” Mr. Trump said, “and I’ll come back here and I’ll make sure it never happens.”
Late Thursday, the National Capital Planning Commission gave final approval for the president’s 250-foot triumphal arch, which will be constructed between the Lincoln Memorial and Arlington National Cemetery.
The NCPC, which acts as the federal government’s planning agency for the region and is stacked with Trump allies, voted 8-4 to greenlight the project after almost 9 hours of public comments from members of Congress, veterans, architects and Washington, D.C., and Virginia residents.
However, a federal judge is weighing whether to temporarily block construction of the arch.
