WASHINGTON - U.S. President Barack Obama sought Wednesday to cast the intensifying health care debate in terms that matter to ordinary people, promising to offer more savings, security and treatment to millions. Assailing his critics, he declared, "This debate is not a game."

In remarks prepared for the start of his prime-time news conference, Obama said he was determined to help the people who write him letters or speak to him at town halls expressing frustration about paying their health care bills or hanging onto their coverage.

"This debate is not a game for these Americans, and they cannot afford to wait for reform any longer," Obama said. "They are looking to us for leadership. And we must not let them down."

Holding his 10th extended news conference, Obama was renewing a message that the White House says he cannot pound enough: making health coverage affordable and sustainable is so vital that anything less will erode the economic stability of families, businesses and even the government.

The stakes are huge not just for everyday Americans, but also for Obama, who is putting much of his credibility on the line to gain passage of congressional legislation soon.

The complex work of getting bills through the House and Senate is proving difficult. Republican leaders contend Obama's effort and the emerging bills are rushed and risky, and members of Obama's own Democratic Party are split on how to structure and pay for a daunting overhaul.

Obama sought to get beyond that and connect with Americans - and, in turn, the White House hopes, to pressure Congress. "I understand how easy it is for this town to become consumed in the game of politics, to turn every issue into a running tally of who's up or who's down," he said.

His words came as House Speaker Nancy Pelosi said Democrats have the votes to pass a massive health care bill in that chamber, prompting surprise and some criticism from conservatives within her party.

Congress is struggling to figure out how to pay for adding millions to the ranks of the insured and slowing the long-term costs of health care in the U.S.

In his comments, Obama reiterated his pledge that any bill he signs will not add to the nation's soaring deficit. "And I mean it," he said.