Tall order: Everything you need to know about Trump's border wall requirements. Source: News Corp

Tall order: Everything you need to know about Trump's border wall requirements. Source: News Corp

HE promised to build a “big, beautiful wall” between Mexico and the USA, and it seems President Trump is intent on delivering just that — at least on the US side.

New specifications released for Mr Trump’s much-debated wall say it’s got to look nice on the US side, and presumably menacing on the Mexican side, with no instructions for aesthetics for the “other” side.

It’s just got to be “physically imposing” in height — ideally, the specs say 9.14 metres high — although at least 5.4 metres “may be acceptable”, according to design specifications for wannabe wall contractors.

Oh — and make it hard to climb without a ladder, and make it difficult to use “common and more sophisticated climbing aids” like grappling hooks, the design specs say.

To thwart anyone going under or through, it must be sunk 1.82 metres into the ground, and able to withstand for at least 30 minutes — but preferably more than four hours — attempts to bust through with a “sledgehammer, car jack, pick axe, chisel, battery operated impact tools, battery operated cutting tools, Oxy/acetylene torch or other similar handheld tools.”

And while you’re making it look nice on the US side, make it “aesthetically pleasing in colour” to blend it into the landscape — which probably rules out the suggestion from one Twitter wag that it be coated in glitter on the US side.

The specifications were found in a pair of contract notices posted to a government website further detailing President Donald Trump’s promise to build a “big, beautiful wall” at the Mexican border, and calling for proposals.

They were made public late Friday by Customs and Border Protection, the Homeland Security Department agency that will oversee the project and eventually patrol and maintain the wall.

One of the requests calls for a solid concrete wall while the other asks for a see-through structure.

Both walls would have to incorporate electronically controlled gates for vehicles and pedestrians.

The wall, and making Mexico pay for it was a promise President Trump made while campaigning, and includes a provision that contractors use American materials whenever possible.

Nobody’s sure about the cost of the big beautiful wall: estimates have put the project at between US$10 billion and US$25 billion.

Interested wall builders have until the end of March to submit plans, from which a select few 9.1 metre-wide samples will be built in San Diego.

‘WE PREFER NOT TO TOUCH THIS WALL’

Opponents of the wall continue to warn companies against working on it.

Three California politicians have introduced legislation that would penalise firms keen to take part in President Donald Trump’s plan to build a wall along the US-Mexico border.

The legislation calls for California’s two public pension funds —- the largest in the US — to divest from companies involved in the construction of the controversial barrier.

“Californians build bridges not walls,” Phil Ting, one of the three Democratic politicians, said.

The bill follows similar proposals across the US and beyond.

A politician in New York, Nily Rozic, earlier this year introduced a bill calling for the state to boycott firms that work on the wall.

Local officials in San Francisco on Tuesday submitted a similar proposal.

Mexican construction firms have also been warned against taking part in the project.

On Tuesday, the French construction group Vinci said it was not interested in helping build the wall.

“I have to take into account the reality of my company, our culture, our way of doing things and our sensitivities, not only those of my American colleagues, but around the world,” the company CEO Xavier Huillard told French television.

“For these reasons, and this is not at all a value judgment on the United States, we prefer not to touch this wall.”

TRUMP UNDETERRED

Trump has bragged in recent days that the wall is ahead of schedule, though it’s unclear from the latest contract notices if any firms have submitted wall proposals or if any such submissions have been rejected, AP reports.

The government has not said where the wall will be built, though the contract notices suggest some pieces of a new wall could replace existing fencing that stretches over about 1130 kilometres of the roughly 3200 kilometre border.

The current fencing includes 4.5 metre steel posts set several centimetres apart, designed to keep people from crossing, and shorter posts intended to block cars.

Border Patrol agents are constantly repairing holes in the structure.

The Department of Homeland Security reported earlier this month that the number of border arrests dropped about 44 per cent from January to February, the lowest monthly tallies since at the least the start of the 2012 budget year.