The former head of the United Nations has urged Iran to build on a historic deal reached with world powers in November and work toward a final settlement over its contested nuclear program.

Kofi Annan, who is heading a group of ex-world leaders known as "The Elders," met Iran's Foreign Minister Mohammad Javad Zarif Monday. Semiofficial Fars news agency quotes him as also praising Iranian President Hassan Rouhani's proposal of a "World Against Violence and Extremism," endorsed by the U.N. last year.

Annan is accompanied by former Finnish President Martti Ahtisaari, South Africa's Nobel Peace Laureate Desmond Tutu and Mexican ex-president Ernesto Zedillo. The group, formed in 2007, is made up of 12 former global leaders who according to their website try "to promote peace, justice and human rights."