The two-day summit will bring together senior officials from the world's major emerging economies, including Brazil, Russia, India, China and South Africa.
Russian President Vladimir Putin will participate in the BRICS summit's plenary session via a video link, while Foreign Minister Sergey Lavrov will attend the summit in person.
Earlier in the day, Iranian Foreign Minister Abbas Araghchi arrived in Brazil to attend the BRICS summit.
Also earlier in the day, Indian Prime Minister Narendra Modi arrived in Brazil for his fourth visit, aiming to strengthen India-Brazil ties in trade, defense, and energy during the BRICS summit and bilateral talks with President Lula.
Cooperation between the BRICS states and the countries of the Global South and East is a determining factor for the entire global economy, the Russian president's deputy chief of staff, Maxim Oreshkin, earlier said.