Donald Trump indicated his neighbours will have to stump up for the new border security – although he conceded it may pay “indirectly” in the form of a new trade agreement.
This agreement would replace the North American Free Trade Agreement (NAFTA), which Mr Trump today described as a “bad joke”.
He said America currently suffered a huge trade deficit to Mexico and a new deal would provide Washington with billions of dollars, which could then fund the wall.
And he also hit out at critics who argued he was already scaling-back the wall itself, claiming some parts would need to be see-through or porous to protect wildlife.
He tweeted today: “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.
“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 US.
“The $20 billion dollar Wall is ‘peanuts’ compared to what Mexico makes from the US.
“NAFTA is a bad joke!”
He later moved on to the importance of the wall, claiming it was necessary to protect America.
During the US presidential election campaign he said Mexico was not sending “their best” to America and instead letting “bad hombres” cross the border.
He tweeted this afternoon: “We need the Wall for the safety and security of our country. We need the Wall to help stop the massive inflow of drugs from Mexico, now rated the number one most dangerous country in the world.
“If there is no Wall, there is no Deal!”
And in an interview earlier this morning he again threatened to terminate the free trade agreement with Mexico unless he gets his way.
He said he knew it would make “a lot of people unhappy” but said it would actually be “good”.
Mr Trump said: “We’re renegotiating NAFTA now. We’ll see what happens. I may terminate NAFTA.
“A lot of people are going to be unhappy if I terminate NAFTA. A lot of people don’t realise how good it would be to terminate NAFTA because the way you’re going to make the best deal is to terminate NAFTA.
“But people would like to see me not do that.”