WASHINGTON (Reuters) -- U.S. Defense Secretary Robert Gates has said diplomacy and sanctions rather than military action are the way to persuade Iran to change its nuclear program as divisions emerge in the Iranian leadership.
Iran's nuclear dispute with the West intensified last week after Tehran disclosed that it is building a second uranium-enrichment plant.
"While you don't take options off the table, I think there's still room left for diplomacy," Gates said on CNN's "State of the Union."
The Pentagon chief said military force would only gain time but not convince Iranians to abandon their quest for nuclear weapons.
Gates said the secrecy with which Iran had been building the underground nuclear facility behind the back of the international community put Tehran in a weak position.
"The Iranians are in a very bad spot now because of this deception, in terms of all of the great powers," Gates said.
"There obviously is the opportunity for severe additional sanctions. I think we have the time to make that work."
Iran, which says its nuclear program is for electricity generation and not weapons production, will meet the United States and five other powers in Geneva for talks on October 1
U.S. Secretary of State Hillary Clinton said Iran must present "convincing evidence" at that meeting.
"We are going to put them to the test on October 1," Clinton told CBS's "Face the Nation" in an interview broadcast on September 27. "They can open their entire system to the kind of extensive investigation that the facts call for."
Gates said sanctions would prove more effective after "deep fissures" emerged in Iran since disputed elections
"We are seeing some divisions in the Iranian leadership and society that we have not seen in the 30 years of the Iranian revolution," Gates said.
Both interviews were taped before Iran test-fired missiles
on September 27 to show it is prepared to head off military threats.