MILWAUKEE (AP) — President Obama's top health care official urged Wisconsin Gov. Scott Walker on Friday to reverse course and accept $10 billion in federal funds to help expand the state's Medicaid program.

Kathleen Sebelius, the secretary of the U.S. Department of Health and Human Services, said the money would pay for costs that are currently being absorbed by taxpayers and community hospitals.

"I'm hoping the governor and Legislature will take a new look at this opportunity," she said.

Sebelius visited a Milwaukee clinic Friday, part of a two-state swing that included a stop in Detroit a few hours earlier. In both cities she talked to people who already signed up for health care through the online federal marketplace or were in the process.

Her Wisconsin visit came a day after Walker, a Republican who opposes the new health care law, called a special legislative session to extend the deadline for moving 77,000 Wisconsin residents off Medicaid until April. Walker stiffened Medicaid eligibility in the state budget, forcing people off the state's BadgerCare plan. He said the extension would give people time to sign up for private insurance on the marketplace and prevent lapses in coverage.

Sebelius applauded Walker's decision, saying it would keep people from falling through the cracks. But she repeated that Walker should go a step further by accepting the federal funds.

Medicaid expansion was a key part of the federal health care overhaul but was optional for states. The federal government will pay the full cost of the new coverage from 2014-2016, then phase down to 90 percent.

Walker isn't likely to change his mind on the federal funds. His spokesman, Tom Evenson, said Wisconsin shouldn't be building its health care future on the promise of continued funding from the federal government considering the "constant financial uncertainty" coming out of Washington.

"How can we expect to depend on the federal government to keep its promise on Medicaid funding, when they can't even manage to run a website properly?" he said in an email.

The federal website has been plagued with problems since it launched Oct. 1. People have complained about being unable to register or having the website time out before they complete their session.

When asked Friday about progress on the website, Sebelius referred to a briefing about its recent improvements, including faster loading times and fewer people being bumped off the site. She acknowledged that plenty of work still needs to be done.

While Sebelius toured the Progressive Community Health Centers in Milwaukee, Walker's office released a letter asking the U.S. Department of Health and Human Services for an additional measure of flexibility in implementing the health care law. The law allows qualified residents to use tax credits to purchase a plan in the federal exchange, and Walker proposed letting people use tax credits for any insurance plan — not just those on the exchange.

"Allowing Wisconsinites to use the subsidies for which they qualify with an insurer of their choice provides a very reasonable alternative to the federal exchange," he wrote.

The letter wasn't sent to reporters in time to ask Sebelius for reaction.

Sebelius spent her time in the Milwaukee clinic observing as counselors guided a couple of uninsured residents through their options under the law. She also spoke with Noelle Stordock, a 23-year-old Milwaukee woman who'd been having trouble getting insurance because of a pre-existing condition with her digestive tract.

Stordock told Sebelius she had trouble navigating the federal website so she came to the clinic two weeks ago for help. A counselor spent an hour signing her up, and now Stordock is enrolled in a plan for $151 per month.

"I feel great about it," Stordock said.