WASHINGTON, March 20, 2010: President Obama delivered his second message to the Iranian people for the festival of Nowruz, which marks the new year, releasing a video on Saturday in which he again offered Iran’s leaders engagement with the United States.

But Mr. Obama tempered his offer for diplomatic dialogue with a threat of international sanctions if Tehran does not rein in its nuclear ambitions.

“We are working with the international community to hold the Iranian government accountable because they refuse to live up to their international obligations,” Mr. Obama said, according to excerpts of the video message released by the White House Friday evening.

But he added that “our offer of comprehensive diplomatic contacts and dialogue stands.”

Mr. Obama sent a Nowruz message last year as well, in a video with subtitles in Persian.

“In this season of new beginnings, I would like to speak clearly to Iran’s leaders,” Mr. Obama said last year. “My administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties among the United States, Iran and the international community. This process will not be advanced by threats.”