The statement is set to be filed in the Congressional Record one day before lawmakers vote on a House resolution aimed at blocking the emergency declaration, the Post reported.
Members of the House are expected to pass the resolution, forcing the Senate to vote on the measure in the coming weeks, according to Politico. The news site noted that "several of the chamber's Republicans have already expressed unease with the president's decision to circumvent lawmakers."
Trump on Feb. 15 signed the national emergency declaration to funnel over $6 billion in funds from the Treasury Department and the Pentagon to pay to build the border wall, Cox Media Group's Jamie Dupree reported.
The national emergency declaration is already facing several legal challenges, including a lawsuit filed by the attorneys general of 16 states.