The Army chief of staff remains hopeful of growing the Total Force to more than 1.1 million soldiers, about 100,000 more than now authorized by law.

Testifying before a Senate panel, Gen. Mark A. Milley, the Army’s 39th chief of staff, said he’d like to see the Regular Army grow to 540,000 to 550,000 soldiers in the next decade, while the Army National Guard would grow to 350,000 to 355,000 and the Army Reserve would grow to 205,000 to 209,000.

A June 1 list of unfunded Army priorities asks for $3.1 billion to pay for a 17,000-soldier increase as part of the fiscal 2018 budget, which as submitted to Congress would hold the Regular Army at 476,000, the Army National Guard at 343,000 and the Army Reserve at 199,000. The Regular Army would get 10,000 of the additional troops, while the Guard would get 4,000 and the Reserve would get 3,000.

Extra soldiers are needed because the Army is busy, with 180,000 soldiers serving in 140 countries, and because the U.S. “is increasingly being challenged,” Milley said.

The future force size is under discussion in the Pentagon as part of planning for the 2019 budget and a strategic-readiness review ordered by Defense Secretary Jim Mattis. Milley described the review as “rigorous and detailed,” looking at force size, capacity and capability.