President Donald Trump looks at his phone during a roundtable with governors on the reopening of America's small businesses, in the State Dining Room of the White House, June 18, 2020, in Washington. (ALEX BRANDON / AP)

The top health official in Tulsa, Oklahoma, where President Donald Trump will hold a re-election rally on Saturday night, said Wednesday that he is "absolutely" concerned that the indoor rally could become a "super spreader" of the novel coronavirus that could lead to more deaths.

Bruce Dart told a news conference that he had recommended the event be postponed until it was safer to bring large groups together indoors

Bruce Dart told a news conference that he had recommended the event be postponed until it was safer to bring large groups together indoors. He also urged people over age 60 who wanted to attend to "please stay home. Seek other ways to participate virtually."

On Wednesday, state officials reported a new one-day high of 259 coronavirus cases.

"We're in the middle of a pandemic," Dart said. "If you want to use your voice, do it safely, wear a mask, social distance. Coming together is a definite possibility of seeing increased infections and increased deaths from those infections."

Tulsa Mayor G.T. Bynum, a Republican, said he was "honored" that his city was chosen to host the president as he returns to the campaign trail. He noted that the event would be the first presidential rally in Tulsa since President George H.W. Bush visited more than 20 years ago.

"The fact that this president, coming out of this event, would single out our city and say, 'That's a city that did it the right way, that's a city that's reopening the right way,' and want to come here? I do take it as an honor," Bynum said. He added that "any rational person looking at any large group of people" would have concerns about the weekend event, but that it would be up to attendees to wear masks and use hand sanitizer.

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Bynum said that it was not his decision to postpone the event and that he didn't control bookings at the BOK Center, the sports arena that signed a contract with the Trump campaign.

Tulsa Police Chief Wendell Franklin said that the temperature for Saturday was expected to reach 90 degrees. "Prepare for hours and hours inside of a concrete jungle, if you will," he said.

In addition to Oklahoma, nine other states are seeing their highest seven-day average of new coronavirus cases per day since the pandemic started months ago, according to a CNN analysis of data from Johns Hopkins University through Tuesday. The states are Alabama, Arizona, California, Florida, Nevada, North Carolina, Oregon, South Carolina and Texas.

Meanwhile, New York City, once the center of the US outbreak and where more than 21,000 people have died from the virus, is "on track" to enter its second phase of reopening as soon as Monday if there isn't a resurge there, Governor Andrew Cuomo said Wednesday.

Under the state's plan, outdoor dining, some in-store shopping, hair salons, barbershops, and some offices in the city would reopen, with social distancing and restrictions on capacity. Playgrounds will also reopen then, city officials have said.

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A prime indication that New York state is on the way back from the pandemic was Cuomo's other announcement. He said that on Friday, he would end his daily briefings, which have drawn national attention. He would hold them afterward as needed, he said.