Heidi M. Przybyla

USA TODAY

Hillary Clinton said she did not disclose her pneumonia diagnosis earlier because she "didn't think it was going to be that big a deal" and called on the press to hold Donald Trump to the "same standard" of transparency.

Clinton called in to CNN on Monday evening, in her first interview since she was recorded leaving a Sept. 11 anniversary ceremony in New York City stumbling and being held up by aides.

"I'm feeling so much better. and obviously I should have gotten some rest sooner," she said. "I probably would have been better off if I'd just pulled down my schedule on Friday but like a lot of people I just thought I could keep going forward and power through it and obviously that didn't work out so well." Her doctor had told her to rest for five days, advice she ignored.

Clinton also said she will release more health information, while arguing that she's been far more transparent than her Republican competitor. "We know the least about Donald Trump of any candidate in recent American history," she said, including his foreign investors and businesses. Clinton noted that she's already released a full medical report with details similar to those Republican Mitt Romney and President Obama disclosed in the 2012 election. That's in addition to 40 years of tax returns and tens of thousands of emails, said Clinton.

Meantime Trump is refusing to release his tax returns and so far he's only released a four-paragraph medical note from his doctor without many specifics. "I think it’s time he met the same level of disclosure that I have for years," said Clinton. "The American people deserve to know what he is up to and what he is hiding,” she said.

Her campaign has also come under criticism for failing to inform the press of her diagnosis, which was made on Friday. On Sunday, Clinton left Ground Zero around 9:30 a.m. ET because she was feeling unwell. Video from outside the event appeared to show her knees buckling as she got into her van.

The press traveling with Clinton remained inside the event for nearly an hour and a half without any information about what was happening after she left. A statement at 11 a.m. said that Clinton left after feeling “overheated.” There was no more information given, besides confirmation that she had arrived home nearly two hours after leaving her daughter's, until after 5 p.m. when the press received a statement saying she'd been diagnosed with pneumonia on Friday.

On CNN, Clinton acknowledged "maybe we weren't fast enough" in getting the information out.

Earlier on Monday campaign spokesman Brian Fallon said that additional details about Hillary Clinton's health status would be made public "in the next few days" but that there was "no other undisclosed condition."

Trump was also at the memorial in New York on Sunday, and the campaign did not even coordinate with his press pool so that they could attend.

"It’s so strange," said Clinton. "As soon as it became clear I couldn’t power through, we said what was going on."

Contributing: William Cummings