President Trump said Sunday that Sen. Lindsey Graham's sudden death is a “big blow” to the Safeguard American Voter Eligibility Act, calling in to NBC News's Meet the Press to address the loss of one of the bill's most prominent Senate backers.

Graham, the South Carolina Republican, had been among the most visible Senate advocates for the SAVE America Act, which would require documented proof of U.S. citizenship for voter registration.

Trump's remarks came shortly after news of Graham's death broke Sunday, with the president using the call to underscore the legislation's significance while mourning the senator's passing.

The bill faces a narrower path through the Senate without Graham's advocacy. No replacement sponsor has been named publicly as of Sunday evening.

Congress returns from recess next week. Senate Republican leadership has not yet indicated whether they will move to assign a new floor manager for the legislation or delay the push.