The summit, hoping to bridge divisions between members Iran and the United Arab Emirates over the Gulf conflict, is being held as the United States and Iran resume tit-for-tat strikes in their six-month-old war.
That followed a pause in fighting for much of August, while the Iran-aligned Houthi rebels in Yemen tightened their grip in the Red Sea region.
Negotiators had agreed on a joint declaration unlikely to name any country but which will condemn unilateral war by any country, four sources told Reuters, adding that the bloc's leaders were expected to approve the document later on Saturday.
The foreign ministry of host India did not immediately respond to a request for comment on the declaration.
Foreign policy experts said the key test for the bloc would be finding language on the Middle East crisis that both Abu Dhabi and Tehran could accept, clearing the way for a joint declaration.
Such a joint statement was unlikely to influence the current geopolitical landscape, but would demonstrate unity by a grouping of emerging nations against economically debilitating policies such as Western sanctions, they said.
The BRICS bloc is seeking to raise its profile by influencing international rules and demanding the reform of institutions such as the World Bank, IMF and WTO, which some members view as being dominated by Western powers.
Leaders attending the summit are Russian President Vladimir Putin, China's Xi Jinping, Iran's Masoud Pezeshkian, South Africa's Cyril Ramaphosa and Abu Dhabi Crown Prince Sheikh Khaled bin Mohamed bin Zayed Al Nahyan, among others.
New Delhi, which has strong ties with the United States, Russia, Israel, Iran and the Gulf Arab states is engaged in a diplomatic balancing act, with Prime Minister Narendra Modi pushing BRICS members to boost trade cooperation, reduce barriers, and expand business opportunities.
The need to bridge the Iran-UAE divide over the US-Israeli war on Iran and produce a consensus summit declaration, however, has been an immediate concern for BRICS diplomats and officials.
UAE, after being hit by Iranian missiles since the war began, suspended all trade and financial transactions with Iran in August.
The BRICS group includes Brazil, Russia, India, China, South Africa, Egypt, Ethiopia, Indonesia, Iran and the United Arab Emirates.
It was set up in 2009 to challenge a world order dominated by the United States and its Western allies.
Together, its members account for more than 40 per cent of the world's population and almost a quarter of the global economy.
15°C