Hours before her husband Joe Biden is to take oath as vice president, Jill Biden said her husband was given the choice of being either secretary of state or vice president.

During an appearance with Joe Biden on the Oprah [Images] Winfrey Show on Monday, Jill's remarks that her husband was given a choice startled him and he tried to hush her up.

"Joe had the choice of being secretary of State or vice president," Jill said as her husband turned his fingers to his lips to say 'shh' and then the couple and the audience broke into laughter.

She then seemed to realise she'd said something she wasn't supposed to have.

This revelation came after Biden told Oprah that after Obama [Images] offered the job of VP he asked for some time to think about it and talk it over with his family.

A clip telecast by ABC News quoted Jill Biden as saying: "I said, 'Joe if you are secretary of state you will be away, I'll never see you,'" Jill Biden said.

"We will see you at a state dinner once in a while. But I said if you are vice president, the entire family, because they worked so hard for the election, they can be involved... They can come to our home, they can go to events, they can be with us and that is what is important to us."

The clip showed Oprah turned to the VP-elect, asking, "Were you worried about being number two because you wanted to be number one?"

"I think Barack was worried about it," the former senator said with a laugh.

So far, the Obama campaign had maintained that Hillary Clinton [Images] was the first choice for the job of secretary of state and offer to her was the president-elect's first major decision.

No immediate comment was available from Clinton.

Elizabeth Alexander, spokesperson for the vice president-elect, said: "To be clear president-elect Obama offered vice president-elect Biden one job only... to be his running mate."

A statement by Alexander said: "And the vice president-elect was thrilled to accept the offer. While the statement denies that Obama ever offered Biden the secretary of state job, it does not rule out the possibility of the two having discussed it."