Bolivia's president is seeking new allies and overseas investment
Bolivian President Evo Morales has arrived in Iran to discuss trade and closer ties with his Iranian counterpart Mahmoud Ahmadinejad.
His visit follows a trip made by Mr Ahmadinejad to La Paz last year, during which he pledged a $1.1bn (£600m) investment in the Andean nation.
The trip will be closely watched by the US, which has tense relations with Tehran over its nuclear programme.
Mr Morales has also been in Libya, for talks with leader Muammar Gaddafi.
Bolivia and Libya recently established diplomatic relations and the two men were expected to sign energy agreements.
Little in common
Mr Morales and his trade delegation were met from the plane at Tehran airport by Iran's Industries Minister Ali Akbar Mehrabian.
He was due to meet Mr Ahmadinejad later in the day, Iranian press reported.
Iran's president is said to be interested in Bolivia's uranium reserves
Bolivia had described the trip as an attempt to reach out to other nations "rejected by the international community".
Mr Morales, Bolivia's first indigenous president, described his country and Iran as "two friendly and revolutionary countries" that are strengthening ties.
In a recent speech, he had said Iran's efforts to provide economic and political backing would "support the peasant struggle in Latin America".
Iran's investment will be directed at boosting bilateral economic and agricultural ties, from milk processing plants, to TV and radio stations to funding hydrocarbon and hydroelectric exploration.
Reports also suggest Mr Ahmadinejad is interested in Bolivia's reserves of uranium and lithium for use in Iran's nuclear projects.
The growing relationship between the two governments has raised eyebrows amongst Bolivia's right-wing opposition and in the United States - which takes a dim view of Iranian influence in its backyard, the BBC's Andres Schipani in Bolivia says.
To some analysts, Iran is seeking to gain geopolitical control in Latin America with the aid of Venezuela's leftist President Hugo Chavez, an unconditional ally of Mr Morales.
Mr Morales has joked on several occasions that he is part of the "axis of evil".
But apart from the fact that both presidents are strong critics of the US, analysts say there is very little in common between Mr Morales and Mr Ahmadinejad.