'The Wall is the Wall': Trump lashes out at John Kelly for saying his campaign promise was 'uninformed'
Gen. John Kelly (Wikimedia Commons) and Donald Trump (AFP)

President Donald Trump renewed his campaign promise to make Mexico pay for a physical wall -- in an apparent rebuke of his chief of staff, John Kelly.

The White House chief of staff told Democratic lawmakers on Wednesday that Trump's campaign comments about the border wall were "not fully informed," and the president lashed out early Thursday morning on Twitter.

"The Wall is the Wall, it has never changed or evolved from the first day I conceived of it," Trump said. "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."

Kelly told the Washington Post that there would not be a wall paid for by Mexico, and White House advisor Kellyanne Conway said last week that Trump had recently learned geographic barriers such as rivers and mountains might obviate the need for a physical wall.

“Certain things are said during the campaign that are uninformed,” Kelly told the newspaper. “One thing is to campaign, another thing is to govern. It’s really hard.”

Trump said last week that he would use NAFTA renegotiations to force Mexico to pay for a wall.

"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.," Trump claimed. "The $20 billion dollar Wall is 'peanuts' compared to what Mexico makes from the U.S. NAFTA is a bad joke!"

Kelly confirmed his comments late Wednesday on Fox News, which the president frequently watches and reacts to on social media.

“He has evolved in the way he looks at things,” Kelly told the conservative network. “Campaign to governing are two different things, and this president has been very flexible in terms of what’s in the realm of the possible.”

The president's tweets came about eight minutes after Fox News replayed portions of Kelly's interview with the network's Bret Baier.