U.S. Vice President Joe Biden says he is withholding judgment on Iran's presidential election, as protests continue in Tehran over election results showing a landslide re-election victory for President Mahmoud Ahmadinejad.  

Vice President Joe Biden says the United States has questions and doubts as to whether Iran's presidential vote was free and fair.

"Is this the accurate response we are getting?  Is this the result of the Iranian people's wishes?  The hope is that the Iranian people - all their votes have been counted, and they have been counted fairly," said Biden, speaking on NBC's Meet the Press program.  "But, look, we just do not know enough [to make that judgment]."

The vice president said the United States must accept Iran's official results "for the time being".  But he added that careful analysis is required, and that actions taken by Iran's government do not lend credence to its claims of a free and fair vote.

"It sure looks like the way they are suppressing speech, the way they are suppressing crowds, they way in which people are being treated that there is some real doubt about that [the accuracy of vote count].  I do not think we are in a position to say," he said.

Biden expressed surprise over President Ahmadinejad's reported margin of victory - especially in urban areas where Iran's opposition appeared strongest.

But if the Obama administration is reacting with caution and a wait-and-see approach to Iran's election results, some Republicans are far less circumspect.  Former Massachusetts Governor and presidential candidate Mitt Romney spoke on ABC's This Week program.

"The election is a fraud.  The results are inaccurate," said Romney.  "And you are seeing a brutal repression of the people."

Romney said that President Barack Obama's efforts to reach out to the Muslim world show no signs of producing a moderating effect on America's adversaries, such as Iran.

Vice President Biden dismissed any suggestion that Iran's disputed election results will complicate efforts to promote dialogue between Washington and Tehran.

"Talks with Iran are not a reward for good behavior.  They are only a consequence of the president making a judgment that it is in the best interest of the United States of America - our national security interests - to talk with the Iranian regime," said Biden.

President Ahmadinejad says his margin of victory in Friday's vote was so large that it cannot be questioned.  Official results showed him beating his reformist challenger nearly two-to-one. Sunday saw a second day of clashes between protesters and security forces, while tens of thousands of Ahmadinejad backers took to the streets to show their support for the president.