Large crowd of protesters on Keshavarz Boulevard in Tehran

President Barack Obama has condemned the violence that was used to quell peaceful Iranian demonstrators last month in the aftermath of Iran's disputed presidential election. But Mr. Obama says direct diplomatic engagement with Iran continues to be an important goal.

In a recent interview with the New York Times, President Obama said, "We've got some fixed national security interests in Iran not developing nuclear weapons, in not exporting terrorism, and we have offered a pathway for Iran to rejoining the international community."

Reactor building of the Bushehr nuclear power plant in southern Iran

Under President Obama, the U.S has offered full U.S. participation in multilateral talks with Iran over its nuclear program. The other participants would include Britain, China, France, Russia and Germany, who, along with the United States, make up what is known as the P5 + 1. So far, Iran has not responded positively to the offer.

In an interview with ABC news, Vice President Joe Biden said that the P5 + 1's offer says to Iran that "we're prepared to sit down and negotiate with you relative to your nuclear program." The ball is in the Iranian government's court, said Mr. Biden, and its leaders still face a choice:

"They either choose greater isolation, and from the whole world, or they decide to take a rightful place in civilized, big, great nations."

During his recent visit to Moscow, President Obama said the prospect of Iran's achieving a nuclear weapons capability "raises the prospect of a nuclear arms race in the Middle East which would endanger global security."  The policy of the U.S., Mr. Obama said, is to try to resolve the matter through diplomatic channels.