Hillary Clinton: 'Happy to Campaign for Barack and Joe' Tune into GMA Tuesday 7 a.m. EST for an exclusive interview with Sen. Clinton.

 -- ALBANY, N.Y. -- Weighing in on Gov. Sarah Palin's impact on the presidential race, Sen. Hillary Rodham Clinton says in an interview to be broadcast Tuesday 7 a.m. EST on Good Morning America that she has full confidence in Sen. Joe Biden as Sen. Barack Obama's running mate, praising his knowledge of the economy and world affairs.

Asked to respond to Palin's assertion that she thinks Obama is "regretting not picking [Clinton] now" -- with many former Clinton supporters now saying they will support the McCain-Palin ticket -- Clinton demurred, saying she's excited to campaign for Obama and Biden.

Watch Good Morning America's Exclusive Interview with Sen. Hillary Clinton at 7 a.m. Eastern.

"We have a great Democratic vice-presidential candidate," Clinton told ABC's Diane Sawyer, aboard the "Good Morning America" "Whistle-Stop Express." "Joe Biden is a friend of mine. He's been a strong leader both on issues here at home when it comes to the economy and stresses on middle class working families, and he understands the strategic challenges that we face around the world. So I'm very happy going out campaigning as hard as I can for both Barack and Joe."