REBECCA ROBERTS, Host: Here's more from NPR's Mike Shuster.</s>MIKE SHUSTER: The United States is leading the effort to impose tougher sanctions. On Friday, Secretary of State Clinton expressed the belief that Iran won't move until there's a new sanctions vote in the Security Council.</s>HILLARY CLINTON: Contrary to recent suggestions, Iran has not indicated any interest in or accepted the standing offer of the P5-Plus-1 to discuss international concerns over its nuclear program. Rather, Iran's senior officials continue to say they will not talk about their nuclear program with us.</s>MIKE SHUSTER: The U.S. ambassador to the U.N., Susan Rice, says the meeting in Tehran should help to clarify the matter.</s>SUSAN RICE: I think the progress that the P5 is making, in fact, perhaps strengthens President Lula's hand as he delivers a message in Tehran that we hope will be, pressure is mounting. Iran continues to have a choice. Assuming it continues to make the wrong choices, that pressure will intensify.</s>MIKE SHUSTER: Abbas Milani, director of Iran Studies at Stanford University, says that does not appear to be working.</s>ABBAS MILANI: They have essentially based their entire foreign policy strategy on the idea that they can use China, Russia and now Brazil and Turkey to break any international resolution against them.</s>MIKE SHUSTER: There's no doubt Iran wants to avoid more sanctions, says Muhammad Sahimi, who writes for the website Tehran Bureau.</s>MUHAMMAD SAHIMI: They don't want any new sanctions because they know that it will worsen the already bad economic situation in Iran. And that, together with the political unhappiness and repression, that would make the situation very explosive.</s>MIKE SHUSTER: Mike Shuster, NPR News.
The president of Brazil is due in Tehran Sunday, in an effort to head off U.S.-led sanctions against Iran in the U.N. Security Council. Tehran has maintained it is unfazed by economic sanctions, but this effort at mediation by Brazil suggests Iran's government is working hard to avert another round of sanctions, likely to come to a vote in the Security Council next month.