Washington (CNN) White House budget director Mick Mulvaney said Tuesday the White House plans to use monies in a border security spending increase to initiate construction of the border wall at the core of President Donald Trump's 2016 campaign.

Mulvaney said the Trump administration will use several hundred million dollars of a $1.5 billion border security spending increase approved in the soon-to-be-approved bipartisan budget deal to begin work on the wall.

"When you heard in the last 48 hours about the deal, did you think we could build this?" Mulvaney said, pointing to a picture of 20-foot high steel wall on the US-Mexico border. "I bet you didn't. Nobody did. OK."

That's despite the fact Democrats touted the agreement as a win and claimed it blocked new funding for border wall construction.

"The (budget deal) does not fund President Trump's immoral and unwise border wall or create a cruel new deportation force," House Minority Leader Nancy Pelosi said Sunday in a statement.

Read More