US President Barack Obama has renewed his administration's offer of dialogue and diplomacy with Tehran, a year after his offer of a new beginning with Iran failed to achieve concrete results.
Obama, who addressed Iranians in a new videotaped appeal to mark the observance of Nowruz - an ancient festival celebrating the arrival of spring - has pledged to pursue aggressive sanctions to prevent Iran from getting nuclear weapons.
Iran, which has refused to halt its uranium enrichment program, denies it is seeking to build a nuclear bomb and says its nuclear program is aimed at generating electricity.
Obama said Washington was committed to a "more hopeful" future for the Iranian people despite US differences with Iran's government.
During his first year in office, Obama marked Nowruz with a then unprecedented message offering Iran a "new beginning" of diplomatic engagement with the United States.
But Tehran rebuffed Obama's gesture and relations soured further when Iranian authorities cracked down on opposition protesters after a disputed election last June, drawing US condemnation.
The United States has agreed with Britain, France and Germany on a draft proposal for a fourth round of sanctions that would place new restrictions on Iranian banks and target the Revolutionary Guard and firms linked to it.
Washington has been struggling to win over China and Russia, both veto-wielding members of the UN Security Council and key allies of Iran, to agree to more aggressive sanctions.