Democratic presidential candidate appeared to stumble yesterday as she left 9/11 event
Donald Trump has said he hopes his rival for president will make a swift recovery after she appeared to collapse at a memorial.
Hillary Clinton seemed to buckle while waiting to get into a minivan at a ceremony to mark 15 years since the 9/11 terror attacks in New York, and she needed help from her security detail.
It has since been revealed that she is suffering pneumonia and is on antibiotics.
Her doctor, Lisa R Bardack, said Mrs Clinton is "recovering nicely" but has been urged to modify her campaign schedule after becoming overheated and dehydrated during the September 11 Commemoration Ceremony.
Speaking to Fox News, Mr Trump said: "I hope she gets well soon... and gets back on the trail... and we'll be seeing her at the debates."
The Republican candidate, who has questioned Mrs Clinton's health during his campaign, added: "We have to see what's wrong. Whatever it is, I'm ready."
The Democrat, who has been advised by her doctor to rest, has cancelled a campaign trip to California while she recovers.
Video footage emerged of Mrs Clinton swaying and then apparently stumbling before being supported by officials as she got into a black vehicle while leaving the memorial.
Following the incident, the 68-year-old went to recuperate in her daughter's Manhattan apartment - but there was no information on whether she required medical attention.
As she left the building two hours later, she waved to reporters and said: "I'm feeling great. It's a beautiful day in New York."
Mrs Clinton was scheduled to attend fundraisers on Monday and Tuesday in California, as well as appear on the Ellen DeGeneres talk show.
It is unclear whether she intends to continue campaigning closer to home, or whether her plans to campaign in Las Vegas on Wednesday will also be disrupted.
Mr Trump has repeatedly raised questions about his rival's health and whether she has the energy to serve as president.
And in his Fox News interview he went on to promise to release the results of his latest physical examination, saying: "Hopefully they're going to be good. I feel great. I'll be releasing very, very specific numbers."
During Mrs Clinton's speech at a campaign rally earlier this month in Cleveland, she was interrupted by a coughing spell.
When she attempted to continue speaking after drinking some water, she quipped: "Every time I think about Trump I get allergic."
In December 2012, Mrs Clinton suffered a concussion and shortly after had a blood clot.
A letter released by her doctor in July described the candidate as being in "excellent health" and "fit to serve" in the White House.
Mrs Clinton's allies says this latest incident shows her resilience as a candidate, with former aide Peter Daou arguing:
"After being diagnosed with pneumonia, Hillary Clinton ran a two-hour national security meeting, gave a press conference, and spent an hour and a half in the heat at a September 11 event.
"It was an impressive feat of physical strength that undermined weeks of health conspiracies."
Nonetheless, the health episode is the latest setback for Mrs Clinton's campaign.
On Friday, she was accused of insulting millions of Americans by saying half of Mr Trump's supporters belong in a "basket of deplorables" of racists, homophobes, sexists, xenophobes and Islamophobes.
The Democratic nominee later said she regretted her remarks at an LGBT fundraiser in New York.