Brazilian President Luiz Inacio Lula da Silva on Tuesday denounced the makeup of the UN Security Council as a legacy of colonialism, although he acknowledged the challenges in achieving long-sought reform.
"The exclusion of Latin America and Africa from permanent seats on the Security Council is an unacceptable echo of the practices of domination of the colonial past," Lula told the UN General Assembly.
He called for a "comprehensive review" of the United Nations Charter, both to reform institutions and to address priorities including the fight against climate change.
But he added: "I am under no illusions about the complexity of such reform, which would go against ingrained interests that maintain the status quo."
The Security Council's five veto-wielding permanent members are legacies of the victors of World War II -- Britain, China, France, Russia and the United States.
President Joe Biden, in his own address to the UN General Assembly, said the United States supported expanding the Security Council, the world body's most powerful institution.
"We must build a stronger, more effective and more inclusive United Nations. The UN needs to adapt and bring new voices and new perspectives," Biden said.
The US ambassador to the United Nations, Linda Thomas-Greenfield, said last week that the United States supported two permanent seats for Africa as well as a new elected seat for small island states, which are particularly vulnerable to climate change.
Some UN watchers say that Biden's rhetorical support for reform is a no-risk strategy as the United States expects rivals Russia and China to block any move that would dilute their power.
And Washington, for its part, has rejected the idea of giving any new members veto power.
Brazil for years has been part of a joint push with Germany, India and Japan for the four powers to gain permanent Security Council seats.
Foreign ministers from the four countries met Monday and reiterated their support for their joint bid.