New York: Democratic presidential candidate Hillary Clinton has cancelled a campaign trip to California because of her diagnosis of pneumonia, a campaign official said on Sunday.

Clinton was scheduled to leave for California on Monday morning for a two-day swing that included fundraisers and a speech on the economy.

After the incident: Hillary Clinton's campaign said the Democratic presidential nominee left the 9/11 anniversary ceremony in New York early after feeling "overheated." Credit:AP

No other details about her travel were available. Hillary Clinton was diagnosed with pneumonia on Friday, her doctor said, after the candidate appeared to faint while abruptly leaving the September 11 commemoration in New York.

In a statement, Dr Lisa Bardack said the 68-year-old politician had been treated for allergies and was found during a follow-up evaluation on Friday to have pneumonia.