The Pentagon will cut funding from military projects like schools, target ranges and maintenance facilities to pay for the construction of roughly 282 kilometers (175 miles) of fencing along the U.S.-Mexico border, diverting a total 3.6 billion U.S. dollars to President Donald Trump’s long-promised barrier.

Projects in 23 U.S. states, 19 countries and three U.S. territories would be stalled or killed by the plan, though just 1.1 billion U.S. dollars in cuts would strike the continental U.S., according to a list released Wednesday by the Pentagon. Almost 700 million U.S. dollars would come from projects in U.S. territories, with another 1.8 billion U.S. dollars coming from projects on overseas bases.

Trump’s move would take the biggest step yet in delivering on his promise to build a wall to block immigrants from entering the country illegally. But it may come at the expense of projects that the Pentagon acknowledged may be difficult to fund anew. Capitol Hill Democrats, outraged over Trump’s use of an emergency order for the wall, promised they won’t approve money to revive them.

A senior defense official said the Pentagon is having conversations with members of Congress to urge them to restore the funding. The official agreed that the department has “a lot of work ahead of us,” considering that Congress has given no guarantee it will provide money for the defunded projects. The official was not authorized to discuss the details publicly so spoke on condition of anonymity.

In addition, new stretches of fencing proposed along the Rio Grande and through a wildlife refuge in Arizona promise to ignite legal battles that could delay the wall projects as well.

The military base projects facing the chopping block tend to address less urgent needs like new parking at the U.S. Military Academy at West Point, New York, and a variety of small arms ranges at bases in Wisconsin and Oklahoma. But a “cyber ops facility” in Hampton, Virginia, and the expansion of a missile defense field at Fort Greeley, Alaska, face the ax, too.

Trump has so far succeeded in building replacement barriers within the 1,053 kilometers (654 miles) of fencing built during the Obama and Bush administrations. The funding shift will allow for about 185 kilometers (115 miles) of new pedestrian fencing in areas where there isn’t any now.

“The wall is being built. It’s going up rapidly,” Trump said Wednesday. “And we think by the end of next year, which will be sometime right after the election actually, but we think we’re going to have close to 805 kilometers (500 miles) of wall, which will be complete.”