Said McCain: "You know it just wouldn't be appropriate to have a festive occasion while a near tragedy or a terrible challenge is presented in the form of a natural disaster, so we're monitoring it from day to day and I'm saying a few prayers, too."
He commented in an interview taped for "Fox News Sunday."
Democratic presidential nominee Barack Obama, in his first direct comment on McCain's unexpected running-mate choice, said he had called her on Friday to wish her luck "but not too much."
McCain and Palin made a morning stop at Tom's Diner in Pittsburgh's trendy Southside neighborhood. The running mates, with spouses in tow, greeted patrons and posed for pictures. Palin's daughters Willow and Piper were also on hand, with Willow carrying Palin's 4-month old son, Trig.
The first-term Alaska governor told reporters she was having fun in her new role. "It's great to see another part of the country," she said. She also said she'd managed to get a little sleep during the night.
"We're used to not getting too much sleep," she said, nodding her head toward the sleeping infant.
The Democratic team of Obama and Joe Biden also began their day with a diner stop - in the Youngstown, Ohio, suburb of Boardman - as they pressed on with their post-Democratic convention bus tour of Rust Belt battleground states.
Obama said in a television interview that he had wished Palin luck "but not too much luck on the campaign trail" in a brief congratulatory phone call on Friday. He told CBS' "60 Minutes" he had yet to meet Palin but "she seems to have a compelling life story. Obviously, she's a fine mother and an up-and-coming public servant."
Of his own choice for a ticket-mate, Obama said Biden "can step in and become president. And I don't think anybody has any doubt about that."
He also said he wanted the "counsel and advice of somebody who's not going to agree with me 100 percent of the time." The Delaware senator, who chairs the Senate Foreign Relations Committee, has a reputation for outspokenness. "Joe Biden doesn't bite his tongue," Obama said in the interview that was taped Friday night in Pittsburgh.
