President Donald Trump is expected to both sign a spending bill and declare a national emergency to secure funding for his long-promised wall along the U.S.-Mexico border, the White House announced Thursday.

The move would attempt to bypass congressional approval to spend billions of dollars on the border wall, which he originally vowed Mexico would pay to build.

“President Trump will sign the government funding bill, and as he has stated before, he will also take other executive action ― including a national emergency ― to ensure we stop the national security and humanitarian crisis at the border,” White House press secretary Sarah Huckabee Sanders said in a statement.

Senate Majority Leader Mitch McConnell (R-Ky.) privately cautioned Trump earlier this month to avoid declaring a national emergency over wall funding, warning the decision could spark backlash from members of his own party, The Washington Post reported.

Congress could pass a resolution against the declaration, McConnell had reportedly warned the president. Congressional disapproval would force Trump to consider his first-ever veto.

Several Republicans have spoken out against Trump’s threats in recent weeks to declare a national emergency. Sen. Marco Rubio (R-Fla.) said last month that doing so would be “a terrible idea” and could set a bad precedent.

McConnell announced Trump’s intentions to declare a national emergency before the White House announcement and ahead of a congressional vote Thursday on a bill that would fund the government for the remainder of the fiscal year and avoid another partial shutdown.

Lawmakers from both parties tentatively reached an agreement on the bill Monday that would allocate $1.375 billion for 55 miles of “pedestrian fencing” along the U.S.-Mexico border ― a fraction of the president’s $5.7 billion demand for more than 200 miles of concrete barriers.

House Speaker Nancy Pelosi (D-Calif.) said Democrats may file a legal challenge against Trump’s declaration.

“First of all, it’s not an emergency what’s happening at the border. It’s a humanitarian challenge to us,” Pelosi told reporters during a press conference Thursday.

Pelosi suggested Republicans could regret the precedent set by such a declaration, hinting that a future Democratic president could declare an emergency on gun violence.

“The precedent that the president is setting here is something that should be met with great unease and dismay by the Republicans,” she said. “And of course we will respond accordingly when we review our options.”