Washington (CNN) A Republican congressman who opposes President Donald Trump's emergency border wall declaration said Sunday he believes Trump "is violating our constitutional system" with the declaration.

The comments from Rep. Justin Amash of Michigan, who serves on the House Oversight Committee, came as he discussed the declaration, which Trump made last month to unlock additional funding to construct his proposed wall along the southern border.

"I think the President is violating our constitutional system. And I don't think Congress can grant legislative powers to the President by statute," Amash told CNN's Jake Tapper on "State of the Union." "You can't just pass a statute that says, 'The President now has appropriations power and bypass Congress.' "

Amash said he thinks his Republican colleagues who support the move are abdicating their constitutional responsibilities, but that he doesn't "think that they are all intending to do that." He added that Republican members of Congress who argue the President was granted this power by Congress are probably not "thinking to themselves, 'Oh, I just want the President to violate the Constitution.' "

Amash, who is one of 13 Republicans in the House who voted with Democrats to pass a measure to block Trump's declaration, told Tapper that "we have to protect our own power."

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