Top officials from the Army, Navy, Air Force and Marine Corps insisted they would protect funding for troops already deployed overseas, but said the military would be less ready to respond to other disasters or crises if the cuts went through.

Hale said the cuts would not apply to money that had already been put under contract, which meant that most contracts signed before Jan. 2, 2013 would not need to be renegotiated -- averting billions of dollars in change fees expected by some executives.

“Both because of the law and the way we’d implement it ... I don’t see those sorts of large cancellation fees,” Hale said, adding that the department would also seek to avoid severance costs wherever possible.

However some longer-term contracts, like the Air Force’s deal with Boeing Co for 179 new refueling planes, would be affected, according to Air Force officials.

Air Force Vice Chief of Staff General Larry Spencer told the hearing on Thursday that he did not expect to have to cancel the tanker contract with Boeing, but said the payment schedule might have to be renegotiated, depending on the size of the cut.

That in turn could prompt a change in the schedule or even an increase in the previous price negotiated, he said.

“As we go down the thousands of contracts and thousands of lines that’s the type of process that we have to go through with every contract,” Spencer said.

Hale said he still hoped Congress could reach a deal to avoid sequestration, but said the department would begin planning how to implement the cuts over the next month, followed by more detailed efforts in the subsequent six weeks.

“We’ll wait as long as we can to begin this process, again in hopes that it is halted, but we won’t wait so long that we won’t have this department ready if in fact it goes into effect on January 2,” Hale said.