JD Vance Sworn in as US Vice President

The transcript is a repetition of an oath-taking ceremony where James David Vance pledges to support and defend the U.S. Constitution, bear true faith and allegiance, and discharge the duties of his office without reservation. The ceremony concludes with congratulations to the Vice President.

What does he vow to discharge faithfully?

What phrase concludes the oath taken by James David Vance?