KABUL, Afghanistan (CNN) -- Afghanistan's president is downplaying accusations of widespread fraud in his country's recent elections, but he's emphasizing the importance of a runoff for the sake of ensuring peace and stability in his nascent and war-torn democracy.

"We must have a second round," said Hamid Karzai, speaking in a taped and exclusive interview for the Fareed Zakaria GPS show that airs Sunday on CNN. "If we don't do that, we would be insulting democracy. And I pledge to respect the vote of the people."

In the first interview since a runoff was announced, Karzai said there were so many claims of widespread corruption in the election two months ago that he started to believe that the voting was fraud-laden. In fact, he said, he too began to doubt the results...