RICHMOND -- Gov. Tim Kaine refused to discuss Tuesday his prospects for becoming the Democratic Party's vice presidential candidate but insisted that heightened speculation is not distracting him from running state government.

"It's a very busy time right now, and I'm very focused on working with my team to make sure Virginia is being run well," Kaine said in a telephone interview.

Democratic presidential candidate Barack Obama is considering Kaine as a running mate, according to news reports posted Monday night. The Washington Post reported that Kaine has told associates he is in "very serious" talks with the Obama campaign about joining the ticket, but also has cautioned that several candidates are under consideration.

Kaine, a national co-chairman of Obama's campaign, repeatedly declined to discuss the matter during a Tuesday morning appearance on Washington, D.C., radio station WTOP.

"I don't talk about my conversations with the campaign," Kaine said. "I save my advice, thoughts, et cetera for the campaign and don't really share them. And I didn't endorse Senator Obama to get anything or get appointed to anything."

Kaine still has more than 17 months remaining in his term as governor, and speculation about his political future comes at a time when the state is facing fiscal pressures caused by a sluggish economy. Kaine's administration recently imposed spending and hiring restrictions on most state agencies, and raised the possibility of layoffs in anticipation of continued slow revenue growth.

Kaine said in an interview that his administration is dealing with the budget problems "in a significant way" as he prepares for an Aug. 18 presentation to the General Assembly's key money committees. The Democratic National Convention begins one week later.

"Obviously, I've got a lot of work to do on this," Kaine said.

Kaine was the first governor from outside Obama's home state of Illinois to endorse the senator's presidential bid and has campaigned for Obama in several states. Obama is mounting a serious challenge to Republican John McCain in Virginia, a state that no Democratic presidential candidate has won since 1964.

If Kaine were to leave office before his term expires, Republican Lt. Gov. Bill Bolling would succeed him. Bolling has announced plans to run for re-election in 2009 and back Attorney General Bob McDonnell's campaign for governor. But that arrangement could change if Kaine leaves office early.

Larry Sabato, director of the University of Virginia Center for Politics, said Tuesday that both Republicans told him Bolling would be the 2009 nominee for governor if he succeeds to the job before the GOP's nominating deadline. McDonnell spokesman Tucker Martin declined to comment on the speculation, saying, "We don't discuss hypotheticals."