The United States is raising the stakes in its bid to halt Iran's nuclear program, putting the issue on a "pressure track," top US general David Petraeus said Sunday.

"I think that no one at the end of this time can say that the United States and the rest of the world have not given Iran every opportunity to resolve the issues diplomatically," Petraeus said.

"That puts us in a solid foundation now to go on what is termed the pressure track. That's the course on which we are embarked now," Petraeus, the head of US Central Command, told NBC television's "Meet the Press" program.

President Barack Obama's administration has talked about a dual-track approach to dealing with Iran's suspect nuclear activities, involving efforts to engage Iranian leaders backed up by the threat of further sanctions.

Petraeus also said that Iran's recent actions on its nuclear program have led US intelligence agencies to update a December 2007 estimation that seemed to downplay the threat posed by Tehran's atomic program.

"There is no question that some of the activities have advanced during that time. There is also a new national intelligence estimate being developed by our intelligence community in the United States," he said.

“We'll probably hear more on that from the International Atomic Energy Agency when it meets here in the next week or so. Clearly, its new director expressed concern about the activities."

Petraeus noted that UN Security Council nations are also "expressing their concern" about Tehran's atomic aims. 

Source: Agencies