By SHANNON McCAFFREY

Associated Press Writer

ATLANTA - President-elect Barack Obama has waded into Georgia's U.S. Senate runoff, recording a radio ad supporting Democrat Jim Martin, but there's still no word on whether the president-elect will make a personal appearance.

In the spot, Obama thanks Georgians who voted for him Nov. 4, then urged support for Martin.

"The elections aren't over," Obama said. "I want to urge you to turn out one more time and help elect Jim Martin to the United States Senate."

Martin is locked in a hotly contested Dec. 2 runoff with first-term Republican Sen. Saxby Chambliss. The Georgia race has taken on national significance as one of two unresolved Senate races. The other is in Minnesota, where a re-count is under way to determine whether Republican Sen. Norm Coleman or Democrat Al Franken is the winner. Wins in both races could give Democrats the 60 seats needed to beat back Republican filibusters.

The stakes are high, and both parties have brought out the political heavyweights. Republicans John McCain and Mike Huckabee stumped for Chambliss last week, and Mitt Romney is due in Georgia Friday.

Former President Bill Clinton led a rally for Martin on Wednesday, and his vice president, Al Gore, is set to appear Sunday.

About 100 Obama field operatives have been working with Martin's campaign staff to ensure voters turn out for the runoff, crucial for Martin to win in reliably Republican state. But direct involvement carries risks for Obama: If Martin loses, Obama would be tagged with a defeat before he's sworn in.

McCain carried the state by five percentage points Nov. 4.