"It doesn't help isolating Iran," he said. "It's important that someone sits down with Iran, talks with Iran and tries to establish some balance so that the Middle East can return to a certain sense of normalcy."
Lula, who honed his negotiating skills as a union leader, says a new tactic is needed with the Iranians.
"I told President [Barack] Obama, I told President [Nicolas] Sarkozy, I told [German] Chancellor Angela Merkel that we will not get good things out of Iran if we corner them. You need to create space to talk," he said last month.
During his radio show, Lula also proposed a football game in March pitting Brazil's famed national team against a team comprising Israelis and Palestinians.
Security council 'failure'
Ahmadinejad, for his part, supported Brazil's bid to become a permanent member of the UN Security Council.
"It's important that someone sits down with Iran, talks with Iran and tries to establish some balance so that the Middle East can return to a certain sense of normalcy"
Luis Inacio Lula da Silva, Brazilian president
Brazil is to take one of the 10 non-permanent seats - those without the power of veto - in 2010 and 2011.
"We support a reformed UN Security Council and for Brazil to have a permanent seat," Ahmadinejad said.
He said the council "has failed over the past 60 years because of the veto power of a small number of countries, a source of insecurity for several countries in the world".
The first visit by Ahmadinejad to Brazil provides Lula an opportunity to boost the international political clout of South America's largest nation, analysts said.
But Brazilian opposition politicians criticised it, citing concern over Iran's nuclear programme as its human rights record, as well as Ahmadinejad's denial of the Holocaust.
Demonstrations against the visit were staged in Brasilia and other major cities across the country.
Lucia Newman, Al Jazeera's Latin America editor, said: "He [Lula] has faced criticism not only from the Republicans in Washington but also in Brazil itself.
"They [critics] believe he has gone too far; that he's isolating Brazil by going to the side of countries that are considered by some to be, as we know, on the axis of evil."
Lula defended the visit, saying any progress on the nuclear standoff with Iran and on the stalled Middle East peace process required dialogue with all parties involved.
Ahmadinejad's trip follows visits in the past two weeks by Mahmoud Abbas, the Palestinian president, and Shimon Peres, his Israeli counterpart, who called on Lula to use Brazil's influence to help curb Iran's nuclear ambitions.
Iran's nuclear programme, which it says is intended for civilian use, has drawn criticism from Western countries which suspect Tehran is seeking to build a nuclear bomb.
World powers have urged Iran to reconsider its rejection of a UN-drafted deal aimed at a peaceful resolution to its contested nuclear programme.
The deal would have seen Tehran shipping its low-grade enriched uranium to Russia and France where it could be processed to be used as fuel in Iran's medical-purpose reactor.
Instead, Iran wants a direct swap of low-enriched uranium for processed nuclear fuel, taking place on Iranian soil.
Ahmadinejad's visit comes as the military back home engages in large-scale war games centred on protecting Iran's nuclear facilities from attack.
The Iranian leader is set to visit allies in Bolivia and Venezuela next to shore up more South American support.