A former Williams & Connolly partner in Washington who has served as a top U.S. trade official since early last year will be the Trump administration’s nominee for legal adviser at the U.S. State Department, a key position central to the formulation of U.S. foreign policy and one that would have a central role as tensions mount with Iran.

The nominee, Curtis J. Mahoney, would succeed Jennifer Newstead as the Senate-confirmed leader of the State Department’s legal team. Newstead, a former partner at Davis Polk & Wardwell, was hired last year as the general counsel to Facebook. The White House announced its nomination plan on Friday.