WASHINGTON  President Obama sought Wednesday to reframe the health care debate as “a core ethical and moral obligation,” imploring a coalition of religious leaders to help promote the plan to lower costs and expand insurance coverage for all Americans.

“I know there’s been a lot of misinformation in this debate, and there are some folks out there who are frankly bearing false witness,” Mr. Obama told a multidenominational group of pastors, rabbis and other religious leaders who support his goal to remake the nation’s health care system.

As the president returned to the health care debate after two days of silence, the administration encouraged Republicans to take part in the negotiations. Still, Democratic leaders moved ahead with plans to advance a measure next month with or without Republican cooperation.

The White House acknowledged that its handling of the debate had been inconsistent, with Robert Gibbs, the press secretary, saying, “I don’t think anybody here believes we’ve pitched a no-hit game or a perfect game.”