President Donald Trump announced a $175 billion, three-year plan on Tuesday to build a massive new missile defense system, offering some of the most concrete details yet about his vision to protect the country.

“It will be capable of intercepting missiles launched from the other side of the world,” he said in an Oval Office announcement with Defense Secretary Pete Hegseth. “Even if they’re launched from space.”

Trump offered few additional details about the project, dubbed “Golden Dome.” POLITICO reported earlier Tuesday about the planned announcement and the first tranche of funding — $25 billion from Trump’s tax and spending megabill currently winding its way through Congress.

The president signed an executive order in January that initiated the defense system. He called for a multi-layered homeland defense program that would stitch together existing Pentagon programs as well as new, developmental technologies such as space-based sensors and weapons.

Trump and the head of the Space Force, Gen. Chance Saltzman, have suggested much of the work would involve building a software backbone to link current systems with new ones that track, and potentially shoot down, ballistic and cruise missiles. But the Congressional Budget Office has estimated the U.S. would need to spend more than $500 billion over two decades to develop a truly comprehensive missile defense shield, so Trump’s three-year window is an ambitious one.

To fulfill the guideposts laid out by the president, Congress would need to come up with $150 billion more over the next two years and the administration would have to determine how to quickly spend that large sum.

Trump, during the announcement, named Gen. Michael Guetlein, the Space Force’s vice chief of space operations, to lead the project.

“This design for the Golden Dome will integrate with our existing defense capabilities and should be fully operational before the end of my term,” Trump said.