WASHINGTON -- An additional $21 billion to the fiscal year 2017 Defense Department budget started the recovery from the effects of sequestration spending cuts, but Congress must pass the fiscal 2018 request and repeal the Budget Control Act to continue those gains, Defense Secretary Jim Mattis told a Senate subcommittee on Monday.

The secretary and Marine Corps Gen. Joe Dunford, the chairman of the Joint Chiefs of Staff, called for increased defense spending and stable budgets during testimony before the Senate Appropriations Committee's defense subcommittee.

"Your support has put more aircraft in the air, more ships to sea and more troops in the field," Mattis told the panel. "However, we all recognize it will take a number of years of higher funding delivered on time to restore readiness."

President Donald J. Trump requested a $639 billion top line for the fiscal 2018 defense budget. "Our first priority is continuing to improve warfighter readiness begun in 2017, filling in the holes from trade-offs made during 16 years of war, nine years of continuing resolutions and Budget Control Act caps," the secretary said.

Dunford said the proposed budget increase would only maintain forces, and more will need to be done in the years to come.

"While we've been primarily focused on the threat of violent extremism, our adversaries and our potential adversaries have developed advanced capabilities and operational approaches specifically designed to limit our ability to project power," the chairman said.

POWER PROJECTION IS CRUCIAL

Potential adversaries took note of America's success in Desert Storm in 1991 and the country's ability to deploy and sustain hundreds of thousands of troops in Afghanistan and Iraq, Dunford said. "They recognize that our ability project power is the critical capability necessary for us to defend the homeland, advance our interests and meet our alliance commitments," he told the senators.

Russia, China and Iran field a wide range of cyberspace, aviation, maritime and land capabilities, he noted. "Those are specifically designed to limit our ability to deploy, to employ and to sustain our forces," Dunford said.

Russia and China have modernized their nuclear arsenals, the general said, while North Korea has been on a relentless path to field nuclear-armed missiles that could strike the United States.

"In just a few years, if we don't change the trajectory, we will lose our qualitative and quantitative competitive advantage, and the consequences will be profound, in my judgment," Dunford told the senators. "It will adversely affect our nuclear deterrence, our conventional deterrence and our ability to respond should deterrence fail. Alternatively, we can maintain our competitive advantage with sustained, sufficient and predictable funding."

He called the 2018 budget request "an essential step" in fixing problems caused by sequestration and continuing resolutions. "But this request is not going to fully restore readiness or arrest the erosion of our competitive advantage," he said. "Doing that is going to require sustained investment beyond [fiscal 2018]."

CONTINUED GROWTH

Future defense budget recommendations will be informed by Mattis' National Defense Strategy, a process now underway, the chairman said. "However," he added, "we know right now that continued growth in the base budget of at least three percent above inflation is the floor necessary to preserve the relative competitive advantage we have today."

A three percent increase will not build the force needed for the future, he emphasized, but rather would just "maintain the relative competitive advantage that we have today."

Plans call for a 355-ship Navy and growth in the number of Army and Air Force personnel. The United States must modernize its nuclear arsenal, the bedrock of deterrence, Dunford said, and it must invest in technologies and equipment that ensure the United States never has to fight a foe on an equal basis.

To do all this will require a budget growth closer to 5 percent, the general said.

"This budget request holds me accountable to the men and women of the Department of Defense," Mattis told the senators. "Every day, more than 2 million service members and nearly 1 million civilians do their duty, honoring previous generations of veterans and civil servants who have sacrificed for our country. It's my privilege to serve alongside them."

The secretary called on Congress to work with the Defense Department to ensure the United States military remains the best and most powerful force on Earth.

"Many times in the past we have looked reality in the eye, met challenges with the help of congressional leadership, and built the most capable warfighting force in the world," he said. "There is no room for complacency, however, and we have no God-given right to victory on the battlefield."