President Barack Obama told Senate Democrats on Wednesday he'd be willing to stay away from election battles where his presence would not be helpful, a Democratic source said -- an apparent nod to his poll numbers.

Obama's comments came when he and former President Bill Clinton attended the Senate Democrats' issues conference at Nationals Park. Sources at the meeting said Obama assured Democrats that maintaining control of the Senate is his top priority this year.

"I don't remember him (Obama) saying he wouldn't be offended if he wasn't invited (to help campaign), but he certainly acknowledged how low his numbers are in certain states," a source told CNN.

But Obama also noted "they are bad in some states overall," and "that certain people would need him to help in certain parts of those states," that source said.