(CNN) -- President Barack Obama has told Senate Democrats that he's 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 on Wednesday.
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.
According to a CNN/ORC International poll conducted last weekend, Obama's approval rating stood at 45%, with his disapproval at 50%.
Those numbers are slightly better than two months before, when the approval ratings ran at or near all-time lows for the President.
But it's still far below where it stood a year ago, at his second inaugural, when his approval rating stood in the low to mid 50s in most polling.
With a number of vulnerable Democratic senators up for re-election this year, sources at Wednesday's meeting said Obama vowed to do what he could to support Democratic candidates.
The Democratic caucus currently holds a 55-45 majority in the 100-member chamber, but 21 Democratic-controlled seats are up this year as opposed to only 15 Republican seats.
Making matters worse for Democrats is the consensus view that the overwhelming majority of vulnerable seats are currently held by Democrats.
The meeting served as a question-and-answer opportunity between Senate Democrats and the President.
Some Democrats up for re-election asked Obama questions, but they focused on substantive topics, largely avoiding politics, according to one source.
"There was amazingly little politics, virtually no politics," said that source, who called the meeting "positive" and "not defensive" on anyone's part.
A number of Democratic senators facing tough re-elections this year seem to be anything but excited to have the President join them on the campaign trail.
Sen. Mark Begich, a Democrat from red-state Alaska who faces a challenging bid for second term in the Senate, told CNN last week that "I'm not really interested in campaigning" with Obama if the President came to Alaska, he said.
It was a similar story from Sen. Mark Udall. The Colorado Democrat is also up for re-election, but his seat isn't considered that vulnerable as of now.
In an interview with CNN last week, Udall refused to say whether he'd like some help on the campaign trail if the President comes to Colorado, a purple state that Obama won in both the 2008 and 2012.
"We'll see what the President's schedule is, what my schedule is. But Coloradans are going to re-elect me based on my record, not the President's record,"
Democratic Sens. Kay Hagan of North Carolina and Mary Landrieu of Louisiana both have made news in the recent months by not appearing with Obama when he's held an event in their state. Both face challenging re-election campaigns in GOP friendly states.
Republicans are highlighting such instances as proof that Obama is toxic for vulnerable Democrats in red or purple states.
CNN's Paul Steinhauser contributed to this report.