Defense Secretary Ashton Carter wrote Wednesday that the failure of Congress to agree to a long-term funding plan is a national embarrassment, one that is creating doubts among enemies and allies about the U.S. commitment to fighting terrorism around the world.

"It's dangerous for military strategy," Carter wrote in the Wall Street Journal about the lack of a spending plan for 2016. "Frankly, it's embarrassing around the world. And it is deeply dispiriting to the U.S. military's talented people and their families."

Congress is facing several key deadlines in the coming weeks, including the debt ceiling. The ceiling must either be raised by Nov. 3 in order to maintain current spending levels, or spending must be cut back to match the level of federal tax revenues coming in.

Funding for the federal government expires in mid-December, and Congress is looking for a two-year budget plan that will help it write a spending bill for the rest of fiscal year 2016.

But Carter blasted the status quo as unacceptable, and said it tells the world the U.S. is only willing to fund military operations sporadically, and for a few weeks at a time.

"What does it say to our adversaries when we take a paycheck-to-paycheck approach to our nation's defense?" he asked. "What does it say to our friends?"

He said the Defense Department has had to make "painful" choices about spending for the last several years under the sequester.

"The Defense Department has done its best to manage through this prolonged period of budget uncertainty, making painful choices and trade-offs among the size, capabilities and readiness of the joint force," he said.

"I appeal to Congress to act on a long-term budget deal that will let America's troops and their families know we have the commitment and resources to see them succeed, and send a global message that the United States will continue to plan and build for the finest fighting force the world has ever known," he wrote.