WASHINGTON — Health and Human Services Secretary Mike Leavitt is leading the White House's fight on children's health insurance, as President Bush challenged Democrats Thursday to put together a bill he can sign before the program's Sept. 30 expiration date.

House and Senate negotiators are working on a compromise between their versions of the bill passed earlier this year, which may expand the state children's health insurance program, known as SCHIP, and include $35 billion for it — about $30 billion more than the president wants to spend.

Leavitt, a former Utah governor, has been asked by the president to work with states if Congress fails to act and the law expires, which would leave children who are now in the program without health coverage.

Bush has said he would veto earlier versions of the bill. While a final conference report is not finished, what is being discussed so far "has some very serious problems," and time is running out, Leavitt said at a White House news conference Thursday. About 35,000 children in Utah are covered through the program.

At the news conference, Bush urged Congress to "pass a clean, temporary extension of the current SCHIP program" that he can sign by Sept. 30.

"Our goal in passing legislation should be getting something done for those in need, not getting nothing done so politicians in Washington can claim a political victory," he said.

Leavitt recommended that Congress temporarily extend the program so children receiving coverage do not lose it, while lawmakers and the White House continue to work out differences.

"The president would like to see SCHIP reauthorized, and we'd like to get on to the larger question of how do we provide insurance for all Americans," Leavitt said.

Rep. Joe Barton, R-Texas, the top Republican on the House Energy and Commerce Committee, introduced a bill Wednesday that would provide a basic extension of the program for 18 months without the increase in funding or policy changes that have been approved. House Republican Leader John Boehner, R-Ohio, and Republican Whip Roy Blunt, R-Mo., sent a letter to House Speaker Nancy Pelosi, D-Calif., asking for a vote on Barton's bill Wednesday.

Pelosi said she is "disappointed that the president has issued a veto threat this morning against this bill that has so much bipartisan, indeed nonpartisan, support."

"The president is wrong when he says Democrats want a political victory," Pelosi said. "What we want is a bipartisan bill. What we want is health care for 10 million children. That is the goal supported by all Americans, regardless of party, and I hope the president will join us."