(Nexstar Media Wire)- The nation’s top health officials say they are seeing a disturbing surge in COVID-19 cases in the U.S.

As of Wednesday morning, 26 states were reporting an increase in cases. Seven of those reported a record number of hospitalizations.

The U.S. now has 25% of the world’s total cases — and 25% of deaths — even though America only has 4% of the world’s population.

In Washington on Tuesday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, issued an urgent warning: “We are now seeing a disturbing surge of infections. The next couple of weeks are going to be critical in our ability to address those surges.”

His warning came as President Donald Trump campaigned in Arizona, one of the states experiencing a rapid increase in virus cases.

California recorded 5,000 new cases in a 24-hour period, it’s highest since the crisis began.

In Texas, one of the first states to begin reopening, Gov. Greg Abbott now says it is possible that restrictions will return.

“Because the spread is so rampant right now, there is never a reason for you to have to leave your home unless you do need to go out. The safest place for you is at your home,” said Abbott.

There is no statewide mandate for wearing masks in Texas or in Florida, where Gov. Ron DeSantis is still resisting issuing one.

“I think you catch more flies with honey than vinegar. When you attach criminal penalties for something, you’ve got to enforce it, and the question is, in some of the parts of Florida, is that really a good use of resources,” said DeSantis.

A county face mask rule was enforced at Trump’s indoor rally at an Arizona megachurch as the state reported a new single-day record of cases at nearly 3,600.

Fauci gave this advice as he testified about the virus on Tuesday: “Plan A, don’t go in a crowd. Plan B, if you do, make sure that you wear a mask.”

Fauci, along with other top health officials, was testifying before a House committee about the Trump administration’s response to the coronavirus.

Fauci also testified that he was unaware of any delays in testing, despite Trump’s claims last week that he had ordered a slowdown to keep case numbers down.

Trump’s staff said the president was kidding, but later, he said, “I don’t kid. By having more cases, it sounds bad. But actually, what it is is we’re finding people.”

Said Fauci: “To my knowledge, none of us have ever been told to slow down on testing. That just is a fact. In fact, we will be doing more testing.”

As for a possible vaccine, Fauci said, “I still think there is a reasonably good chance that by the very beginning of 2021, that if we’re going to have a vaccine, that we will have it by then.”