Barack Obama believes Hillary Clinton best person to lead US: White House

US President Barack Obama believes that Hillary Clinton is the best person to lead the country, the White House has said, a day after the Democratic presidential candidate fell ill during a ceremony marking the 15th anniversary of the 9/11 attacks in New York.

Brushing aside questions about Clinton's health impacting her presidential campaign, White House Press Secretary Josh Earnest said, "I think it certainly does not impact his (Obama's) assessment that she is the best person in the country to succeed him in the Oval Office".

Later this week, Obama is slated to do a major fund-raiser and hold rallies in support of Clinton.

"He (Obama) has had an opportunity to work closely with her when she was secretary of state. They travelled around the world. She pulled long hours. She bore a significant burden, both mentally and physically. She did not just succeed in that role, she thrived and the interests of the US were well represented as a result of it," Earnest told reporters at his daily news conference yesterday.

"The President, as you have heard him say on many occasions, is confident that she will bring those same skills and that same endurance to the job as President.

"The President has taken a close look at the agenda and philosophy that has been put forward by secretary Clinton. And he has enthusiastically endorsed it. So I think the President's belief that she would be an excellent President of the US is something that you have heard him say many times. And I can tell you there is nothing that happened yesterday that has changed that assessment at all," he said.

He said it is up to the two campaigns to release information about the health of their candidates.

"The President believes that it is the responsibility of the two candidates to make their own decisions about their campaign. What is true is that as President, President Obama every couple of years has asked his physician to put together a memo that we release to the public, detailing the President's health," Earnest said.

"We did something similar when then senator Obama ran for President, as well. And obviously the requirement that the American people have some understanding of the health of their President is I think a pretty common-sense proposition.

"But for individual candidates, they ultimately have to make a decision on their own about what kind of information and what kind of detail about their health they are prepared to disclose," he said.

He said there is a reason that there is a longstanding tradition in this country of individual candidates disclosing information about their health to the American public before the election.

"But I do not have any advice to dispense to the individual candidates about how they should handle this question. What I can do is point you to what Senator Obama did when he was running for this office and what President Obama has done while serving in this office," Earnest added.