President Donald Trump speaks during an event in the Rose Garden at the White House Friday, Feb. 15, 2019 in Washington.

WASHINGTON (AP) Battling with one branch of government and opening a new confrontation with another, President Donald Trump announced Friday he was declaring a national emergency to fulfill his pledge to construct a wall along the U.S.-Mexico border.

Bypassing Congress, which approved far less money for his proposed wall than he had sought, Trump said he would use executive action to siphon billions of dollars from federal military construction and counterdrug efforts for the wall, aides said. The move is already drawing bipartisan criticism on Capitol Hill and expected to face rounds of legal challenges.

Trump made the announcement from the Rose Garden, as he claimed illegal immigration was "an invasion of our country."

Trump's move followed a rare show of bipartisanship when lawmakers voted Thursday to fund large swaths of the government and avoid a repeat of this winter's debilitating five-week government shutdown. The money in the bill for border barriers, about $1.4 billion, is far below the $5.7 billion Trump insisted he needed and would finance just a quarter of the more than 200 miles (322 kilometers) he wanted this year.

To bridge the gap, Trump announced that he will be spending roughly $8 billion on border barriers combining the money approved by Congress with funding he plans to repurpose through executive actions, including the national emergency. The money is expected to come from funds targeted for military construction and counterdrug efforts, but aides could not immediately specify which military projects would be affected.