But as he moves into more familiar territory – the world has long become accustomed to his hearty hugs with Venezuela's President Hugo Chávez – he is buoyed by his first leg in Brazil, a visit that sets this regional tour apart from those of the past.
Mr. Ahmadinejad's welcome by Brazilian President Luiz Inácio Lula da Silva helped him shore up badly needed support, amid disputed presidential elections at home and international attempts to isolate Iran over its nuclear program.
"We can predict the results of a trip to Venezuela or Bolivia. ... But given the importance of Brazil, there was more at stake," says Daniel Brumberg, acting director of the Muslim World Initiative at the US Institute of Peace in Washington, adding that Ahmadinejad has gained much more than his Latin American peers on his trip so far.
Brazil reaffirmed its support of a peaceful nuclear energy program in Iran. Mr. da Silva urged the Iranian leader to seek a "just and balanced solution" with Western nations over its nuclear program, after Iran last week appeared to reject the terms of an Oct. 1 agreement that would have sent its enriched uranium to other nations for further processing – thus allaying international fears that the Tehran could quickly develop a nuclear weapon. In return, Ahmadinejad supported Brazil's push to be a permanent member on the United Nations Security Council.
"[Da Silva] could have used its good relations with the US and its strategic role in the region to prod Iranians at the very least to coming back to the table to honor the agreement [they] seemed to embrace in October over uranium enrichment," Brumberg says. "There must be mild disappointment in the administration that the Brazilian president did not use the moment."
Ahmadinejad moved on to La Paz, Bolivia, on Tuesday, where President Evo Morales greeted him with full military honors, and will later head to meetings with Mr. Chávez in Venezuela, where opportunities for trade and energy deals are expected to be discussed.
No real threat to US
The trip comes as Iran has deepened its presence in Latin America, particularly among presidents such as Chávez take similar anti-US stances. "He's enjoyed some success in making links in the continent, and he'd like to extend that," says Bruce Buchanan, an expert on US and Iranian relations at the University of Texas at Austin.
Most analysts say that the US, while frustrated, has little to fear from a trip that was most likely a relief from pressures both abroad and at home.
"He loves the spotlight, and he loves the limelight," says Gary Sick, an Iran expert at Columbia University in New York. "Iran is in no position to build a strategic beachhead in Latin America that would somehow threaten the US, certainly not in the next four years," when Ahmadinejad's term is over.
Chávez-Ahmadinejad ties raise concerns
Still, his visit in Brazil, the first by an Iranian leader since 1965, lent him a degree of legitimacy he had not yet found in Latin America. Brazil has sought to become a major player on the diplomatic scene to match its growing economic clout. The visit was criticized by New York Congressman Eliot Engel, who called da Silva's welcome a "a serious error."
US leaders are not the only ones who are concerned though; other leaders in the region have also voiced their skepticism, especially the budding relationship between Chávez and Ahmadinejad.
Jamsheed Choksy, professor of Iranian and international studies at Indiana University, says that the Latin America tour is part of a larger effort by Ahmadinejad to woo friends around the world. But "Latin America immediately makes the US look very cautiously," he says. "The question that arises here is whether these diplomatic contacts are simply diplomatic or whether they could lead to nuclear proliferation."
• Matt Clark contributed from Peru.