FORT LEONARD WOOD, Mo.–The Defense Department will ask Congress for additional wartime spending, but leadership hasn’t decided how much more to request, Defense Secretary Ashton Carter said Wednesday.

Carter told reporters he’s said since the first Overseas Contingency Operations (OCO) request was submitted this for fiscal year 2016 that it’s the “nature of warfare” to not know, at the beginning of the year, what everything will cost. The Pentagon is bolstered by what Carter called success in both its counter ISIL efforts and work in Afghanistan. Aerial view of the Pentagon, Arlington, VA

Bloomberg reported Pentagon comptroller Mike McCord told the publication in an interview the request would be worth more than $6 billion, but Carter declined to put a dollar figure on the request, saying only that he’d submit one.

“We haven’t settled on how much those are worth,” Carter said. “We’re still doing those estimates and assessing the situation.”

Carter spent Tuesday and Wednesday traveling between New York and Fort Leonard Wood, Mo. He addressed City College of New York and Stand Up for Heroes audiences in Manhattan on Tuesday, discussing new DoD initiatives to better recruit well-qualified prospects and candidates in challenging territories like the northeast.

Carter on Wednesday spent the day here getting briefings on the Army’s munition training and counter-IED efforts and participated in hands-on demonstrations. These included using the hand-held mine detector ANPSS-14, performing a thermal breach of metal using an exothermic cutting rod and Talon robots.

Carter will spend Thursday attending the U.S. Strategic Command (USSTRATCOM) change of command ceremony and will visit the Air Force Research Lab (AFRL) at Wright-Patterson AFB, Ohio. Air Force Gen. John Hyten replaces retiring Navy Adm. Cecil Haney as the leader at USSTRATCOM.