Bolivian President Evo Morales is in Tehran at the start of a three-day state visit.
Speaking ahead of his trip, Morales said his aim was to boost bilateral ties and encourage Iranian investments in his country. He is scheduled to hold talks with Iranian President Mahmud Ahmadinejad and sign a number of cooperation agreements.
It is Morales's second visit to Iran in two years.
Like his ally Venezuelan President Hugo Chavez, Morales, who heads Bolivia's Movement for Socialism party, has sought increasingly closer relations with Tehran.
In 2007, Ahmadinejad became the first Iranian president to visit Bolivia.
During that trip, the two countries signed an agreement on conducting joint projects worth $1.1 billion over the next five years.
compiled from local and international agency reports