A company that President Donald Trump urged military officials to hire for border wall construction has been awarded a $400 million contract to build a span of new barrier across an Arizona wildlife refuge, according to a Department of Defense announcement Monday.

North Dakota-based Fisher Sand and Gravel Co. won the contract to build in the Cabeza Prieta National Wildlife Refuge in Yuma County, Arizona, the Defense Department said, with a target completion date of Dec. 30, 2020.

Trump has repeatedly pushed for Fisher to get a wall-building contract, urging officials with the Army Corps of Engineers to pick the firm – only to be told Fisher’s bids did not meet standards. Trump’s entreaties on behalf of the company have concerned some officials who are unaccustomed to the president getting personally involved in the intricacies of government contracting.

Trump has been enamored with Tommy Fisher, the company’s CEO who has made appearances on Fox News to promote his firm and insist it would do a better job than those the government had already chosen. The company’s attorneys did not immediately respond to requests for comment late Monday.

Sen. Kevin Cramer, R-N.D., a Fisher booster who has taken the case to the Oval Office, has argued that the company could build the wall faster than any of the current Army Corps contractors. Trump has grown upset in recent months that so few miles have been built, given his campaign promises to construct hundreds of miles of wall to keep immigrants from crossing into the United States via the southern border.

In a statement, Cramer said the company plans to build 31 miles of new barrier.

“I am glad to see more progress being made to secure the southern border, and I am grateful to see a good North Dakota company like Fisher Industries getting some of the work,” Cramer said. “I know they will do very well, performing high quality work at a good bargain, all for the security of the people of the United States.”

Fisher has worked with a number of Trump allies – including former Kansas secretary of state Kris Kobach and ex-White House adviser Steve Bannon – to build new border fence on private land using private donations. After the activist group We Build the Wall hired Fisher to construct a span of new barrier outside El Paso, Texas, the company purchased riverfront property in South Texas where it said it plans to erect a 3.5-mile span of fencing on the banks of the Rio Grande.

The company’s construction plan has not been approved by the International Boundary Water Commission, which regulates construction in the Rio Grande flood plain, but Fisher and We Build the Wall have won praise from senior U.S. Border Patrol officials.

Trump has pledged to complete 450 to 500 miles of new border barriers by the end of next year. So far his administration has build about 85 miles of new fencing, almost all of it in areas where tall steel bollards are replacing smaller, older structures that existed before he took office.