White House budget director Mick Mulvaney doesn't think a government shutdown is a good idea, but if one were to happen, he said it would be a "good" shutdown if it helped Washington fix its spending problem.

"If you wanted to imagine what a good shutdown would be, it would be one that fixes this town," Mulvaney said at the White House. "One that really drives the message back home to people that it really was as broken as they thought it was when they voted for Donald Trump."

Mulvaney was responding to questions about President Trump's tweet that the country needs a "good" government shutdown in September in order to change Senate rules to move a spending bill that Republicans can get behind. Under today's rules, 60 votes are needed, which means Democrats have the power to block any spending bill they want as long as eight Democrats don't vote with Republicans.

Mulvaney said Trump is frustrated by Senate rules that allow Democrats to block his agenda, even though they don't control the chamber.

At the same time, Mulvaney said shutdowns shouldn't be talked about that way.

"It's not a goal and it's not a negotiating tool," he said.