Trump signs order to preserve Oval Office as national monument

US President Donald Trump has signed an executive order that he says will prevent future presidents from making certain changes to the White House Oval Office.

The executive order declares the president's official office, which he has renovated, to be a national monument.

"We're making it a national monument, and 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," Trump told reporters on Thursday.

The order does not prevent future presidents from changing the decor of the famous room.

The document says that it does not "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…