WASHINGTON — The Trump administration wants to build a 30-foothigh border wall that looks good from the north side and is difficult to climb or cut through, according to 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.

The notices 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 CBP contract requests calls for a solid concrete wall, while the other asks for proposals for a see-through structure. It must also be built in a such a way that it would take at least an hour to cut through it with a “sledgehammer, car jack, pickax, chisel, battery operated impact tools, battery operated cutting tools, Oxy/acetylene torch or other similar hand-held tools.”

Trump has said that the wall is ahead of schedule,

As the Trump administration advances plans to erect a multibillion-dollar wall on the Southern border, the leader of Mexico’s national governors association said Saturday in Washington that President Donald Trump’s budget proposal proves that U.S. taxpayers will foot the bill.

Trump has insisted that he will force Mexico to pay for the wall, but Mexican officials have refused. The president’s budget request Thursday included $2.6 billion, mostly for the first stages of the wall. though it’s unclear if any firms have submitted proposals.

The contract notices suggest pieces of a new wall could replace fencing over about 700 miles of the roughly 2,000-mile border. The current fencing of mixed construction includes 15-foot steel posts set inches apart designed to stop people and shorter posts to block cars.

The Government Accountability Office estimates it would cost about $6.5 million a mile for fence to keep pedestrians from crossing the border and about $1.8 million a mile for a vehicle barrier.

Congressional Republicans have said Trump’s wall would cost between $12 billion and $15 billion and Trump has suggested $12 billion. It is unclear how much money lawmakers will ultimately approve for the wall.

Meanwhile, on Saturday Trump said that Germany owes NATO and the U.S. “must be paid more” for providing defense.

Trump tweeted the day after meeting with Germany’s leader.

“Despite what you have heard from the FAKE NEWS, I had a GREAT meeting with German Chancellor Angela Merkel,” he wrote. “Nevertheless, Germany owes vast sums of money to NATO & the United States must be paid more for the powerful, and very expensive, defense it provides to Germany!”