U.S. President Donald Trump said on Tuesday that he will block the Associated Press from the Oval Office and Air Force One until the news agency stops referring to the Gulf of Mexico.

For the first time, President Trump himself said the Associated Press had to change its style on the gulf after the White House began not allowing the news organization to cover several of his events last week.

President Donald Trump made his first reference on Monday to his White House war with the Associated Press—only to vow to maintain its indefinite ban of the news outlet. Trump called the wire service “obsolete” and said he would keep it barred from press engagements until it calls the Gulf of Mexico the “Gulf of America.