An all-out campaign was waged Thursday by US President Barack Obama to drive his historic health care overhaul through Congress, wooing wavering lawmakers and blasting "unacceptable" insurance rate hikes.

Waging an uphill fight for passage of his top domestic priority, Obama was to meet with 11 Democratic House members from the party's progressive wing and then with seven Democratic House centrists, his press office said.

Democratic House Speaker Nancy Pelosi predicted at her weekly press conference that Congress would ultimately approve the far-reaching legislation but warned that she was not taking any Democratic votes for granted.

"Every vote, every legislative vote is a heavy lift around here. You assume nothing, assume nothing in terms of where you were before and where people may be now," she told reporters.

Pelosi declined to set a timetable for a House vote, but White House spokesman Robert Gibbs told MSNBC television "we on scheduled to get something done before we leave" for Australia on March 18.

Obama was piling pressure on lawmakers to sign on to his strategy, which calls for the House to abandon the legislation it approved in November and pass the Senate's version, coupled with "fixes" to that bill.

"I therefore ask leaders in both houses of Congress to finish their work and schedule the vote in the next few weeks. From now until then, I will do everything in my power to make the case for reform," he said Wednesday.