Henry Kissinger undergoes heart surgery

Chinese ambassador to the United States Cui Tiankai (right) and former US Secretary of State Henry Kissinger pose for a photo during an unveiling ceremony of the new logo of the Kissinger Institute on China and the United States in Washington D.C., United States, April 29, 2014.[Photo/Xinhua]

Former US Secretary of State Henry Kissinger, who is credited with opening diplomatic channels with China, underwent heart surgery at a New York hospital on Tuesday.

The 91-year-old Nobel Peace Prize recipient and adviser to two American presidents, had a successful aortic valve replacement at New York-Presbyterian, the hospital said in a statement. "He is resting comfortably," according to a hospital statement.

Kissinger has a history of heart trouble, including undergoing a triple coronary bypass in 1982 and an angioplasty procedure in 2005.

A former Harvard professor, Kissinger served as national security advisor and also as secretary of state for Presidents Richard Nixon and Gerald Ford.

He was Nixon's national security adviser from 1969 to 1973, and secretary of state from 1973 to 1977. Kissinger initiated relations with China in 1972. There had been no official contact between the countries for more than 20 years.

Kissinger shared the 1973 Nobel Peace Prize with North Vietnam’s Le Duc Tho for helping establish a cease-fire in Vietnam. Le Duc Tho declined the honor.

Since his tenure as secretary of state, Kissinger has written his memoirs, several books and newspaper articles. He operates a consulting firm in New York.