President Donald Trump’s 2018 budget plan asks Congress for enough money to build just 60 miles of border wall.

The request for just $1.6 billion in wall funding is found in the budget document released by the Department of Homeland Security, which describes the agency’s 98-page plan for spending its overall 2018 budget of $70.7 billion. According to the document:

A critical element of border security involves building the infrastructure necessary to halt the flow of illegal crossings. The FY 2018 President’s Budget proposes an investment of $2.7 billion for high priority tactical infrastructure and border security technology, including funding to support planning, design, and construction of the border wall. This funding would allow CBP to construct:

32 miles of new border wall system in the Rio Grande Valley Sector,

28 miles of new levee wall in the Rio Grande Valley Sector, and

14 miles of new border wall system that will replace secondary fence in the San Diego Sector.

The budget assumes a cost of all $22 million per mile of new wall or fence.

In April, 100 days after his inauguration, Trump again promised he would build a wall, despite opposition from Congress, saying:

We’ll build the wall. Don’t even think about it. Don’t even think about it. That’s an easy one. We’re going to build a wall. It’s the final element. We need the wall. And it’s a wall, in certain areas where you have massive physical structures, we don’t need, and certain big rivers and all, but we need a wall. And we’re going to get that wall. And the world is getting the message. They know that our borders are no longer open to illegal immigration and that if they try to break in, you’ll be caught and you’ll be returned to your home. You’re not staying any longer.

The border is 2000 miles long. Roughly 654 miles of the border has some barrier, ranging from simple barbed wired to a set of tall, layered walls alongside San Diego. According to the Mercury News, “along the existing wall or fence, 36 miles have double fencing with both primary and secondary barriers, and 14 miles have three layers of fencing, according to Customs and Border Protection. The San Diego area is one of the most fortified, with 46 miles of primary fencing and 14 miles of secondary fencing—and enough room to accommodate the road that runs between them.”

At the proposed pace of 60 miles per year, it will take 10 years to provide double-layer fences to the one-third of the border that now has wiring or walls, and 31 years to double-fence the entire length of border. In contrast, the United States defeated two huge military empires in the four years after 1941.

In a May 23 briefing, agency spokesman David Lapin waved off media questions about the wall. “We’re relying on CBP and the Border Patrol experts to identify the areas of most need” for a wall, he said. “It will be an iterative process over time to address the most critical areas as we go.”

The 2018 budget request actually is only slightly more ambitious that the March supplement request for $1 billion, which was intended to build 48 miles of additional wall.

Many Democratic and GOP members of Congress are loudly or quietly opposing the planned border wall, which would slow the northward movement of low-wage employees and consumers to businesses in Democratic-dominated cities. But some members of Congress want Trump to build the wall faster. Iowa Sen. Chuck Grassley, for example, released a statement during a May 23 hearing in the Senate, saying:

the fact remains that more needs to be done. Congress needs to work with the Administration to find measures to both increase apprehensions and deter illegal entry … Congress should also consider a number of other common-sense measures. Among other things, we should provide more funding for … completing the construction of all 754 miles of border fencing required under the Secure Fence Act.

Democrats, however, hope to wreck Trump’s administration by defeating his primary campaign promise of building a border wall.