Oklahoma Gov. Kevin Stitt said his state is “critically low” on test kits and that he has been pushing the federal government for help.

The shortage of tests means that in many states people who believe they might have contracted the virus can’t know for sure and are told to stay home for weeks. It means health care workers don’t know whether they've contracted the illness even as they treat infected patients and tend to members of high-risk groups, such as the elderly, who might be in the hospital for other reasons. And it means public health officials are left guessing where they should direct resources because they can’t be certain whether there are clusters of cases.

Trump on Thursday insisted that governors have all they need, telling reporters he was hearing “very good things on the ground.”

“I can tell you what we’re doing is working with local governors to get them what they want,” Trump said.

But the president’s words don’t match reality, state and local officials say.

“We’re the boots on the ground. We know what's available,” said Kris Ehresmann, infectious disease division director for the Minnesota Health Department. “Some of the commercial labs do not have the materials they need.”

That’s left states to impose strict criteria on who can be tested, frustrating people across the country who are showing symptoms, worried but were told to wait and see if their cases worsen. In several states, only those who are hospitalized or at high risk, including those with underlying conditions, can be tested.

“Most individuals with mild symptoms do not need to be tested even with expanded testing options,” Indiana State Health Commissioner Kristina Box said during a news conference on Thursday. She added even though commercial labs were scaling up testing capacity in the state, they will still have to limit who is getting the tests. “We still have a shortage of supplies and we need to be mindful of that.”

Shortages and testing backlogs continue to be reported across the country. In Eagle County, Colo., where state officials have reported a cluster of cases, the local hospital, Vail Health, confirmed at least 400 people are waiting to be tested.

White House officials have sent mixed messages, telling states and Congress that supplies were on their way while acknowledging those supplies still might fall short. Last week, NIH infectious disease expert Anthony Fauci lamented to lawmakers that the testing effort to date was “a failing,” and CDC Director Robert Redfield told POLITICO he was not confident the U.S. has sufficient supplies of materials needed to prepare samples for testing.

Still, Trump repeatedly assured governors that supplies were on the way. Meanwhile, the days have turned to weeks, and the shortages persist.

“I feel a little like Charlie Brown and Lucy with the football with the federal government,” said Illinois Gov. J.B. Pritzker.