Defense Secretary Ash Carter has a fired off a letter to Congress warning of the dangers of failing to pass a budget and instead relying on a continuing resolution to fund the military for the next six months.

“In the letter, Secretary Carter says that he is particularly troubled by information that Congress may be considering a CR through May of next year,” spokesman Peter Cook told reporters on Tuesday. “A short-term CR is bad enough, but a CR through May means DOD would have to operate under its constraints for two-thirds of the fiscal year.”