He formerly served as staff officer for Joint Staff Plans and Policy at the Pentagon and defense attache at the US Embassy in Beijing.

At his confirmation hearing in March, Stilwell said the US won't ease pressure on North Korea based only on its pledge to denuclearize.

He also said he believes the sanctions imposed on the North by the United Nations Security Council and independently by the US should continue.

"Slow and patient diplomacy seems to be working," Stilwell said at the hearing. "There's going to be ebb and flow with that, but staying the course and letting the North Koreans know we're not going to pull back just on their word."

Stilwell's confirmation completes the lineup of State Department officials handling Korean Peninsula issues. He is known as a hawk on China.

On the US alliance with South Korea, Stilwell has said it is "iron-clad" and "global in reach," noting it has "only strengthened as we coordinate more closely to achieve the final, fully verified denuclearization of North Korea and welcome it into the family of nations." (Yonhap)