At the start of talks in Geneva with six world powers - Iran presents its proposals - aimed at a breakthrough over its disputed nuclear program.

Details of the Iranian's proposals were not available - but Michael Mann - the spokesman for the European Union's foreign policy chief - said there was a sense of quote: "cautious optimism."

SOUNDBITE: EU FOREIGN SPOKESMAN MICHAEL MANN, SAYING:

"We have come here with a sense of cautious optimism and a great sense of determination, because we believe it is really time now for tangible results."

With growing concerns of a new Middle East war, international pressure has intensified over Iran's nuclear ambitions.

Bringing the U.S., Russia, China, France, Britain and Germany to the table - Tehran's launched the two-day meeting in Switzerland, raising hopes for an end to the gridlock.

Iranian Deputy Foreign Minister Abbas Araqchi.

SOUNDBITE: IRANIAN DEPUTY FOREIGN MINISTER ABBAS ARAQCHI, SAYING:

"We a