Lula, along with Recep Tayyip Erdogan, the Turkish prime minister, made a deal with Iran to ship about half of its enriched uranium to Turkey, restarting the diplomatic process that was initially rejected by Tehran last year.
Both leaders have expressed dissatisfaction with the US' push for sanctions against Iran, challenging the US' role as the only superpower.
The administration of Barack Obama, the US president, condemned the mediation efforts, suggesting that Tehran's compliancy is merely an attempt to stall for more time in which to develop nuclear arms, and announced its own deal with its partners in the UN Security Council to impose strong new sanctions on Iran.
Some Brazilian critics are concerned that this deal may have damaged the country's relationship with the US and will prove a stumbling block for Lula's campaign for a permanent seat in the United Nations.
On Monday's Riz Khan, Celso Amorim, the Brazilian foreign minister, explains why he thinks this deal is an important step forward.
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Source: Al Jazeera