In recent weeks, Iran has rejected a plan to process nuclear material outside the country and tested an upgraded medium range missile believed to be capable of reaching Israel.
A senior advisor to U.S. President Barack Obama, David Axelrod, says Iran's actions belie its long-standing insistence that its nuclear program is intended solely for peaceful purposes.
"Nobody has any illusions about what the intent of the Iranian government is. And the international community is going to have to deal with that if they [Iranian officials] do not change their minds," he said. "Plainly, there are going to be consequences if they do not turn around [cooperate]."
Axelrod was speaking on ABC's This Week program. He said the international community's resolve to limit Iran's nuclear program has grown.
"When we [the Obama administration] came to office, Iran was united and the world was divided in an approach to deal with Iran," he added. "Today Iran is bitterly divided, and the world community has come together. And the president [Barack Obama] has been a big force in bringing them together."
But Mr. Obama's opponent in last year's presidential election, Republican Senator John McCain of Arizona, says the administration's efforts to engage Iran have only served to give Tehran more time to develop it nuclear potential. Appearing on the Fox News Sunday television program, McCain urged swift new sanctions against Iran and unambiguous U.S. support for Iran's political opposition.
"The president [Obama] should stand up for the people who are demonstrating and risking their lives on behalf of freedom on the streets of Tehran. When the president refused to speak up on the first days of those demonstrations [after Iran's presidential election], I think it was wrong," he said.
President Obama decried bloodshed in the wake of Iran's contested presidential vote in June, but was careful not to endorse the opposition which claimed that the election had been stolen by President Mahmoud Ahmadinejad.