President Trump on Thursday vowed to build a border wall despite White House chief of staff John Kelly's recent comment that his campaign promise to do so was "not fully informed."

"The Wall is the Wall, it has never changed or evolved from the first day I conceived of it. Parts will be, of necessity, see through and it was never intended to be built in areas where there is natural protection such as mountains, wastelands or tough rivers or water," Trump tweeted Thursday morning.

"....The Wall will be paid for, directly or indirectly, or through longer term reimbursement, by Mexico, which has a ridiculous $71 billion dollar trade surplus with the U.S. The $20 billion dollar Wall is 'peanuts' compared to what Mexico makes from the U.S. NAFTA is a bad joke!" he added.

Kelly informed members of the Congressional Hispanic Caucus during a visit to the Capitol Thursday that some of the promises Trump made during his campaign would not come to fruition.

"One thing is to campaign, another thing is to govern. It’s really hard," Kelly said.