Former President Bill Clinton says it was hard for his wife, Hillary Rodham Clinton, to decide to give up her Senate seat to become secretary of state in President-elect Barack Obama's administration.

The former president told CNN in an interview aired Wednesday from Hong Kong his wife was "shocked" when she learned by reading newspaper articles that she was Obama's likely choice for the nation's top diplomatic post. She's been a New York senator since 2001.

Deciding to give up her Senate seat "was hard," Bill Clinton said. "She adored being in the Senate."

Clinton says he'll probably be "a helpful sounding board" to his wife, but wasn't expecting any more involvement unless Obama "asks me to do something specific, which I'm neither looking for nor opposed to."