National Security Adviser James Jones said the Obama administration was prepared to move forward with "very tough sanctions" if Iran did not heed international calls to suspend its nuclear program.

"We are on a clear path here for what has to happen next all the while leaving the door open for Iran to do the right thing," Jones said on "Fox News Sunday."


If Iran did take the offer to work with the International Atomic Energy Agency, Jones said, "they would be better off."

"For reasons that are somewhat mysterious but nonetheless constant, they have not walked through that door," Jones said. "And they have not taken us up on the offer."

Iran maintains that its nuclear program is for peaceful energy and medical purposes, but also recently rejected an offer floated by the U.S. to supply medical isotopes. The Islamic Republic also pressed forward with production of 20 percent enriched uranium, announcing on the 31st anniversary of the Islamic Revolution that the first batch had been completed.

White House Press Secretary Robert Gibbs doubted those claims at Thursday's briefing. "We do not believe they have the capability to enrich to the degree they say they are enriching," he said.

Jones said that President Barack ObamaBarack Hussein ObamaRealClearPolitics editor says Trump needs to compromise on border to shift public opinion Obama ‘new blood’ remark has different meaning for Biden  Democratic dark horses could ride high in 2020 MORE had been clear on his intention to give Iran time to accept offers to further its nuclear power capability while stemming nuclear weapons capability. "We're drawing our conclusions based on non-action on the Iranian part and now moving towards a clear set of sanctions," Jones said.

"I think we will get tough as quickly as possible," Jones said. "But you know, whether it happens this week or next week is not the issue."

Jones said that the administration supported the pro-democracy movement in the country but would not out-and-out advocate regime change. But he said that the combination of internal problems within the Tehran government and "very tough sanctions ... could well trigger regime change."