Henry Kissinger, controversial statesman who influenced U.S. foreign policy for decades, has died

Henry Kissinger, one of the most influential and controversial diplomats of the 20th century, died Wednesday at age 100, his firm said. 

Kissinger, who served as secretary of state and national security adviser under Presidents Richard Nixon and Gerald Ford, remained a prominent voice on foreign policy issues long after leaving government in 1977. 

"I work about 15 hours a day," he told CBS News weeks before he turned 100, saying with confidence that world leaders like China's Xi Jinping or Russia's Vladimir Putin would likely take his calls.