US President Barack Obama accused Iran on Tuesday of creating an "electronic curtain" blocking its citizens from using the Internet and social media to full effect.

Addressing ordinary Iranians in a video message marking the Persian new year celebration, Obama acknowledged "continued tensions between our two countries."

But, he insisted that Americans want a dialogue with Iranians despite some three decades of bad blood and Washington's long-held view of the Islamic Republic as a pariah state.

"There is no reason for the United States and Iran to be divided from one another," he said.

Obama's overture was the latest step in Washington's bid to pressure Tehran into abandoning its uranium enrichment program in upcoming talks with the 5+1 – the five permanent members of the UN Security Council and Germany.

Renewing accusations of Iran's suppression of its people, Obama said Iranians were "denied the basic freedom to access the information that they want."

He cited blocking of television and radio signals, monitoring of computers and cell phones and censoring of the Internet.

"Because of the actions of the Iranian regime, an electronic curtain has fallen around Iran," Obama said, adding Washington would move to break Tehran's Internet blockade.

"Today, my administration is issuing new guidelines to make it easier for American businesses to provide software and services into Iran that will make it easier for the Iranian people to use the Internet," he said.

Obama urged Iran to respect its citizens' liberties "just as it has a responsibility to meet its obligations with regard to its nuclear program," adding Iran would be "welcomed once more among the community of nations" if it did so.

"We have learned once more that suppressing ideas never succeeds in making them go away," Obama said.

Mass protests erupted in Iran against the disputed 2009 re-election of Iranian President Mahmoud Ahmadinejad, but were brutally crushed by Iranian security forces.