Leaders of the BRICS group of emerging powers meet on Tuesday to launch a new development bank and a reserve fund seen as counterweights to Western-led financial institutions.
Brazilian President Dilma Rousseff hosts the leaders of Russia, India, China and South Africa in Fortaleza on Tuesday before talks with South American leaders the next day in Brasilia.
The summit will mark the first face-to-face meeting between Prime Minister Narendra Modi and Chinese President Xi Jiping.
For Russian President Vladimir Putin, who visited Argentina and Cuba before coming to Brazil, the trip gives him a chance to hammer home his calls for a "multipolar" world amid tensions with the West over the Ukraine crisis.
"Together we should think about a system of measures that would help prevent the harassment of countries that do not agree with some foreign policy decisions made by the United States and their allies," Putin told Russia's ITAR-TASS news agency.
Russia has been excluded from the G8 group of industrialized powers as punishment for its annexation of Crimea and perceived meddling in Ukraine.
The United States is threatening to impose new economic sanctions on Russia over accusations that it is backing pro-Moscow separatist rebels in eastern Ukraine.
The summit comes as the economies of some BRICS countries, which together represent 40 percent of the world population and a fifth of the global economy, are cooling down. Russia and Brazil are expected to see growth of just one percent this year.
The five emerging nations unveiled in 2013 their plans to create the bank, which aims to rival the Washington-based World Bank while the reserve is seen as a "mini-IMF."
The creation of the bank will give a backbone to the BRICS, which is not a formal international organization, said Marcos Troyjo, Brazilian director of BRICLab research center at New York's Columbia University.
"They are only taking their first steps towards a platform for building consensus on international agenda items such as rules for international trade, joint action at the UN or the WTO," he told AFP, referring to the World Trade Organization.
The bank will have initial capital of $50 billion with each country contributing an equal share, while the reserve will have $100 billion at its disposal.
The bank is "key to foster growth for the BRICS countries," Brazilian industry and commerce minister Mauro Borges said.
For the fund, China will make the biggest contribution, $41 billion, followed by $18 billion from Brazil, India and Russia and $5 billion from South Africa.
Despite their agreement on the need for a bank, the five countries are split on where it should be headquartered.
Shanghai is seen as the frontrunner to host the bank but South Africa insists on having it in Johannesburg. New Delhi and Moscow are the other candidates.
The five nations are also negotiating who should hold the bank's rotating presidency first and the make-up of the board.
The talks in Fortaleza will open a series of marathon summits and bilateral meetings in Brazil.
After the BRICS meet with South American presidents in Brasilia on Wednesday, Xi will launch the China-Latin America forum, highlighting Beijing's growing interests in a region historically tied economically to the United States.
Xi will then travel to Argentina, Venezuela and Cuba.