Defense Secretary Jim Mattis on Monday called on Congress to repeal budget caps on defense that he said are causing confusion in Washington and get back in the "driver's seat" of making annual spending decisions.

The Army and other services should also get behind the push to remove the $549 billion cap for fiscal 2018 by convincing lawmakers of the need for more funding for U.S. forces that are losing their edge over competitors and adversaries, Mattis said during a keynote speech at the annual Association of the U.S. Army conference.

"I am among the majority in this country that believes our nation can afford survival and I want the Congress back in the driver's seat of budget decisions, not in the spectator's seat of automatic cuts," he said.

The Pentagon has bristled for years about the spending limits imposed by the Budget Control Act of 2011, often shorthanded as "sequestration." Mattis testified this year, "No enemy in the field has done more to harm the combat readiness of our military than sequestration."

Sequestration refers to the mandatory across-the-board budget cuts required if Congress exceeds the budget caps spelled out in the six-year-old legislation.

"There are times when those of us who wear the uniform can be rightly condemned for being overly conservative, wanting more insurance, and more boats and planes and guns and tanks, and I understand that," Mattis told the Army crowd. "I think the more we can explain we have the time right now to prepare for war as the best way to prevent war. But should conflict break out, to get money later will not be good enough because we will not have the time at that point."

As if to underscore the point, during a brief question-and-answer session at the conclusion of his remarks, he urged the Army to prepare for war in North Korea.

"It is right now a diplomatically-led, economic-sanction buttressed effort to try to turn North Korea off this path," Mattis said.

"Now what does the future hold? Neither you nor I can say, so there is one thing the U.S. Army can do, and that is you have got to be ready to ensure that we have military options that our president can employ if needed."