Former New York City Mayor Michael Bloomberg (I) said Wednesday that President Trump's proposed border wall with Mexico is "not very practical" and "almost impossible to build."

"I think a wall is not very practical. Number one, it would be almost impossible to build," Bloomberg told CNN's Jake Tapper, when asked if he would support wall funding if tied to a bill to replace or fix a program protecting young people brought to the country illegally as children.

Former New York Mayor Michael Bloomberg says a border wall “is not very practical” and “impossible to build” https://t.co/1a6Ib6fipY — CNN Politics (@CNNPolitics) September 20, 2017

Trump promised during his campaign that Mexico would pay for the wall. He has since said the U.S. would front the funding for the border wall and Mexico would reimburse the U.S.

ADVERTISEMENT

Mexican President Enrique Peña Nieto has vowed that Mexico will not pay for the wall. Trump in Facebook posts this week tried to assure supporters the wall will be built, calling it "non-negotiable."

Trump has also ended the Deferred Action for Childhood Arrivals program which protected people brought to the U.S.illegally as children from deportation.

But in a meeting with Democratic congressional leaders last week, Trump said he would be open to legislation reinstating the program or its benefits in exchange for tougher border security measures, possibly including wall funding.

Bloomberg said a wall "would be very good for the Mexican economy," and the project would likely use Mexican laborers and resources.

"But the wall doesn't add anything," he said. Bloomberg added the wall would only create a barrier for the equal number of Mexicans who leave the U.S. for home.

"We need to have borders where people that want to want to work here, who want to take jobs that Americans don't want to take, and that want to create new businesses can do so," he said.