'You dumb person!' Trump erupts when pressed on his ballooning $1B White House ballroom

President Donald Trump attacked reporters as "dumb" and "stupid" during a rant about the ballroom he wants to build at the White House.

During a press gaggle outside the White House on Tuesday, Trump insisted that his ballroom project was under budget, even as Republicans in Congress sought to allocate $1 billion to help fund its construction after the president said it would be paid for with $400 million in donations.

"It's going up right here. I've doubled the size of it because we obviously need that," Trump shouted over the sound of the Marine One helicopter. "And we're right now on budget, under budget, and ahead of schedule."

The president seemed to become angry after one reporter pressed him on the ballooning cost of the project.

"I doubled the size of it, you dumb person!" he griped. "You double the size. You are not a smart person!"

"Based on a lot of things that have happened over the last year, we doubled the size of the ballroom, so we're going to have a ballroom that's appropriate for the White House," he added. "We doubled the size! The ballroom now is ahead of schedule, and it's a little bit under budget, depending on the finishes that we use."