Hillary Clinton has told supporters she is feeling better and will return to the campaign trail soon, after she appeared to collapse at a memorial.

Mrs 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.

Later on Monday, she tweeted: "Thanks to everyone who's reached out with well wishes. I'm feeling fine and getting better.

"Like anyone who's ever been home sick from work, I'm just anxious to get back out there. See you on the trail soon."


Senior aide Brian Fallon told MSNBC that Mrs Clinton had no other undeclared condition, adding: "I expect that by the middle to the late of the week she'll be back out there on the campaign trail."

Like anyone who’s ever been home sick from work, I’m just anxious to get back out there. See you on the trail soon. -H — Hillary Clinton (@HillaryClinton) September 12, 2016

The Clinton campaign will also release additional medical information in the next few days that should reassure people about the state of her health, Mr Fallon added.

The candidate's doctor, Lisa Bardack, said Mrs Clinton is "recovering nicely" but has been urged to modify her campaign schedule after becoming overheated and dehydrated during the 11 September Commemoration Ceremony.

Image: Mrs Clinton interrupted a speech in Cleveland after suffering a coughing fit on 5 September

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."

He did not mention her health when he spoke to the National Guard Association's convention in Baltimore on Monday, however, preferring to focus on criticising her for suggesting half of his supporters belonged in "a basket of deplorables".

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Democrat Mrs Clinton, who cancelled a campaign trip to California while she recovers, was seen in video footage swaying and then apparently stumbling before being supported by officials as she got into a black vehicle while leaving the memorial.

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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."

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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."

:: Clinton's Medical History In Spotlight After Fall

During Mrs Clinton's speech at a campaign rally earlier this month in Cleveland, she was interrupted by a coughing fit.

When she attempted to continue speaking after drinking some water, she quipped: "Every time I think about Trump I get allergic."

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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."

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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.

::Trump v Clinton - First Presidential debate live on Sky News, 27 September 0200