White House counselor Kellyanne Conway said Wednesday evening that her boss, President Trump, has "discovered" that the wall he wants to build along the U.S.-Mexico border won't need to stretch across the entire nearly 2,000 miles of border.

She was prompted to speak about project, which Trump has been promising since the 2016 campaign, during an interview with CNN's Chris Cuomo.

"What's true is that after conferring with the experts that are involved in this process, Christopher, the president discovered that part of it will be the physical wall, part of it is better technology, part of it is also fencing," Conway said.

"There are rivers involved, I'm told," she added. "There are mountains involved, there's terrain that isn't conducive to building an actual physical structure in some places."

Conway's comments come as Trump has stressed that any legislative deal in Congress to salvage the Obama-era Deferred Action for Childhood Arrivals program, which protects hundreds of thousands of young illegal immigrants for deportation, needs to also include funding for the wall.

Trump himself has conceded in the past that building a wall, for which prototypes have already been built, may not be needed.

”You have mountains. You have some rivers that are violent and vicious. You have some areas that are so far away that you don’t really have people crossing," Trump told reporters in July. “But you’ll need anywhere from 700 to 900 miles.”

He repeated that sentiment during an immigration meeting with a bipartisan group of lawmakers this week.

“We don’t need a wall where you have rivers and mountains and everything else protecting it,” Trump said. “But we do need a wall for a fairly good portion.”

Trump has sought the physical barrier as a way to stem the tide of illegal immigrants and drugs into the U.S. He has also repeatedly pressed Mexico to pay for the wall.