WASHINGTON—A key witness in the contentious Senate confirmation of Defense Secretary Pete Hegseth was assured by Sen. Thom Tillis (R., N.C.) that her sworn statement would carry weight in last week’s vote and could convince Republican senators to oppose the nominee,

The North Carolina Republican said he did his “due diligence” and deferred to the Senate Armed Services Committee endorsement.

Pete Hegseth has vowed to bring his “warrior” ethos to the Pentagon. Democrats had assailed him as unfit for the job, and his confirmation came down to Vice President JD Vance serving as tiebreaker.