The House voted on Friday to approve a waiver to allow Gen. James "Mad Dog" Mattis, President-elect Donald Trump's pick for defense secretary, to serve in the role should he be confirmed.

The vote 268-151, coupled with Senate's passage on Thursday cleared a final procedural hurdle to allow Mattis to serve as defense secretary without having been out of the military for seven years. A law bars newly retired military officers from heading up the Department of Defense. Mattis, who retired in 2013, fell short of the seven-year requirement.

The vote came a day after Mattis' confirmation hearing, a hours-long session in which he called Russia a "principal threat." He joins a growing number of Trump cabinet picks who took strong positing on Russia during confirmation hearings this week. CIA director nominee, Rep. Mike Pompeo, was similarly critical of Russia during his own confirmation hearing Thursday and Secretary of State nominee, Rex Tillerson echoed those sentiments during his hearing on Wednesday.

Senator Tim Kaine, a member of the Senate Armed Services and Foreign Relations Committees said he will support Mattis' confirmation.

"In his testimony before the Senate Armed Services Committee yesterday, he demonstrated a clear-eyed view of our current national security environment and a deep appreciation for the challenges facing U.S. servicemembers and their families," Kaine, a Virginia Democrat said in a statement. "I believe he is well-prepared to lead the Department of Defense and provide the incoming administration with wise and strategic counsel on matters of national security".