NEW YORK: Former US president Bill Clinton underwent a sudden heart operation after complaining of chest pains, but was in good spirits afterwards, his advisor said.

Clinton, 63, was taken to hospital in New York Thursday "after feeling discomfort in his chest," Douglas Band said in a statement sent to AFP.

"Following a visit to his cardiologist, he underwent a procedure to place two stents in one of his coronary arteries."

His wife, Secretary of State Hillary Clinton, rushed from Washington to the Columbia Campus of New York Presbyterian Hospital to be with her husband. The State Department said she decided to delay her departure on a planned trip to the Gulf by one day, to Saturday.Related article:Hillary Clinton delays trip

President Barack Obama telephoned Clinton to wish him a speedy recovery and was told by the ex-president that he felt "absolutely great," a White House official said.

Band also said that Clinton emerged from the operation "in good spirits, and will continue to focus on the work of his foundation and Haiti's relief and long-term recovery efforts."

George W. Bush, a Republican who replaced Clinton in the White House and is now working alongside him as a relief coordinator for Haiti, said he was "glad" to hear Clinton felt better.Related article:Bush 'glad' former president Clinton doing well

In 2004 Clinton underwent quadruple bypass surgery to free four blocked arteries.

On Thursday, stent tubes were inserted into the body to prevent constrictions by unblocking arteries and assisting blood flow.

While in the White House, Clinton famously indulged his appetites, including junk food, but in his post-presidential days he appeared to have been adhering to a stricter diet as well as a busy work schedule.

In a 2005 interview just months after the bypass surgery, he told CNN that prior to going under the knife he realized "I was very close to having a serious heart attack.

"I had big-time blockage. And I felt very grateful to be going under the surgery without serious damage to my heart so I thought I could make a recovery. Still it was kind of a mystical, interesting experience," he said.

Clinton, who is now the special UN envoy to Haiti, has kept up a frenetic pace since he left office in 2001 after serving two four-year terms in the White House.

"He doesn't have an accelerator, but a switch, and that switch is on 23 hours a day, and that is one speed, full speed ahead," James Carville, Bill Clinton's former campaign manager, told CNN.

Just last week Clinton paid his second visit to Haiti in a bid to get aid moving to the Caribbean nation struck by a 7.0-magnitude quake on January 12, and apologized for the slow arrival of relief supplies.

But the former president rejected suggestions he had in effect become governor of Haiti, with which he has had long ties.

"What I don't want to be is the governor of Haiti. I want to build the capacity of the country to chart its own course."

Since leaving office Clinton has through his foundation battled to raise awareness of AIDS, pushed for tsunami recovery in Asia and pressed for more relief to Haiti.

The Arkansas poor boy who rose to the nation's top political office has also travelled the world appearing at conferences, often earning huge fees, or backing his favored causes for no payment.Profile:Clinton: The big-living ex-president who won't slow down

Clinton was sworn in on January 20, 1993 as the 42nd US president and the first Democrat to hold the highest office in 12 years. He won a second term in 1996.

He remains hugely influential on the US political landscape, and is revered by Democrats for presiding over an economic boom time in the United States.

But his scandalous affair with intern Monica Lewinsky during his presidency, and the impeachment proceedings that followed, tarnished his political legacy.

Clinton's foundation, which has raised millions for worthy causes, in 2003 negotiated agreements with several major pharmaceutical companies to discount AIDS drug prices for the developing world, which has been worst hit by the disease but can least afford the medicines needed to treat it.

He was a fierce supporter of his wife's bid to win the Democratic nomination in the 2008 presidential election and only buried the hatchet with the eventual victor, Obama, in late October 2008.

They joined forces for the first time at a rally in Kissimmee, Florida just days before the historic November election.

"The presidential campaign is the greatest job interview in the world. And... you get to make the hire," Clinton told the rally, swallowing his resentment at his wife's defeat.

Washington's ultimate power couple have one daughter, Chelsea, who is due to marry this summer.