WASHINGTON — Virginia U.S. Sen. Mark Warner won’t relax until significant federal debt reduction is accomplished.

"This is whether Congress is up to governing and knocking $4 trillion off the debt. It’s not curing cancer and it’s not defeating Communism. But until we get this dealt with, we can’t do anything else," Warner said.

As he nears the midway point in his first term as a U.S. senator from Virginia, Warner is focused on debt reduction and also fully aware that life in Washington is not as satisfying as being home in Virginia.

"It ain’t being governor,’’ he said during a brief break in his office at the Russell Senate Office Building on Thursday, which happened to be the day of his birthday. "I was the CEO. I could drive the agenda. But here, I’m trying to be part of driving the debate."

Warner has co-led with Sen. Saxby Chambliss, R-Ga., a group known as as the "Gang of Six,’’ three Republican and three Democratic senators.

The group has worked for a year on a way to accomplish the $4 trillion debt reduction suggested by the Simpson-Bowles Commission.

The "Gang of Six’’ has a blueprint that involves spending cuts, raising revenue and reforming entitlement programs such as Social Security, Medicare and Medicaid.

The "Gang of Six’’ proposal has the support of perhaps 45 senators and 100 to 105 members of the U.S. House.

Warner said he needs a 67-vote margin in the Senate and knows there is much work to be done in both chambers of Congress to reach the goals.

Conventional wisdom is that it could be difficult to accomplish the debt reduction in 2012, which is an election year for Congress.

Warner said there is no time to wait. "Nothing gets any easier because the debt goes up. We may not have that much time,’’ he said.

When he ran for the Senate in 2008, Warner said he wanted to be a radical centrist who would work in a bipartisan way to reach solutions.

It was an effective approach when he served as Virginia’s governor from 2002 to 2006.

By reaching out to Republicans in the Virginia House and Virginia Senate, he was able to get passed a half-cent increase in the Virginia Sales Tax passed by legislators in 2004.

The tax increase provided badly needed funds for education. There was also tax code reform.

Virginia Republicans who voted for the sales tax increase earned Warner’s respect, but heard about the vote later from conservatives who branded them as tax and spend representatives.

Warner’s outreach included pickup basketball games and one-on-one meetings in Richmond.

In Washington, besides the "Gang of Six,’’ Warner is now co-hosting monthly bipartisan dinners for groups of 20 senators with veteran Tennessee Republican Sen. Lamar Alexander.

"This is not unlike when I was governor. You are building trust,’’ he said.

Prior to doing this interview, Warner was deep in discussion with Wisconsin Republican Sen. Ron Johnson, seeing what initiatives they could partner on.

Ultimately, Warner said his mind and discussions with other senators come back to debt.

"I’m obsessed with debt. I was a business guy for 20 years and we put Virginia’s finances back in order,’’ he said.

As Warner sees it, the country’s debt problem is a bigger national security threat than terrorism.

As he heads to the Capitol to pose for pictures with a school group from Fairfax County,

Warner recalls how much fun he had as Virginia’s governor.

Small policy initiatives were appreciated, as were his frequent visits to Virginia communities where he savored the people contact.

For a brief time on his birthday, it was déjà vu for Warner.

He posed on the U.S. Capitol steps with 79 students from the Hispanic Leadership Alliance in Fairfax, talking to the students about their education and careers, and briefly conversing with them in fluent Spanish.

He clearly enjoyed the interaction.

On his 57th birthday, Warner still has a perspective about his life that not even the debt deadlock can wipe away.

"I’m very blessed,’’ he said. "I’ve been successful in business, and I loved being governor,’’ he said. "I can make choices."

Still to be answered, is what path he might take in three years when he is up for re-election.

"I’ve not decided what I will do,’’ he said. "I’m focused on where I can add value and build relationships and get to a bipartisan solution on the debt."