Dozens of countries have expressed interest in joining BRICS, a group encompassing Brazil, Russia, India, China and South Africa that views itself as a counterweight to the West and which is meeting this week in Johannesburg.

Argentina, Egypt, Indonesia and Saudi Arabia are thought to be among those most likely to be admitted. Iran has also expressed interest.

China’s leader, Xi Jinping, backs expanding the group. But Prime Minister Narendra Modi of India is said to be concerned about adding nations close to Beijing; India and China have border disputes and tend to consider each other potential adversaries.

Here is a look at some of the nations vying to join.

The addition to BRICS of Saudi Arabia, one of the world’s leading oil producers, would add economic clout to the group and bolster its chances of positioning itself as a rival to the U.S.-led financial order.

BRICS membership looks like an increasingly natural fit for Saudi Arabia, which has cultivated ties with China and — despite its longstanding and tight security relationship with the United States — has pointedly demonstrated independence from American interests in recent years.

Last year, Saudi Arabia cut oil production just when the Biden administration thought it had secured an increase. In February, it restored diplomatic ties with Iran — signing the deal in Beijing. And despite American pressure to support Ukraine in the war with Russia, the kingdom, like other Arab countries, has remained steadfastly neutral.

For Saudi Arabia, it may seem like good geopolitics to cultivate relationships with major partners who, unlike the United States, do not cavil over human rights. But it could also be good business. The country of more than 32 million people, many of them young, is seeking to diversify an almost entirely oil-dependent economy.

Saudi Arabia is the BRICS club’s biggest trading partner in the Middle East, with trade reaching $160 billion last year, the foreign minister, Prince Faisal bin Farhan, said in June.

With nearly 46 million people, Argentina has the third-largest economy in Latin America, after Brazil and Mexico. Its backers in BRICS include India; Brazil, its largest trading partner; and China, with which it has increasingly close financial ties.

Argentina has a history of economic crises and is in the midst of one of its worst. Its currency has plummeted; inflation has hovered around 113 percent for the past 12 months; and nearly 40 percent of the population is impoverished. The country is also struggling to repay a $44 billion debt to the Western-dominated International Monetary Fund.

President Luiz Inácio Lula da Silva of Brazil said on Tuesday that he supported Argentina’s bid, mentioning the country’s struggles with a lack of foreign reserves.

Argentina’s president, Alberto Fernández, was invited to a virtual meeting of BRICS nations last year.

“The BRICS are, for my country, an excellent alternative for cooperation in the face of a world order that has been working for the benefit of a few,” he wrote to the organization in May 2022.

He called the New Development Bank, which was created by BRICS and which Argentina wants to be a part of, “the institutionalization of a new world order focused on development, and away from the financial speculation that has caused so much damage to our countries.”

Iran, which holds the world’s second-largest gas reserves and a quarter of the oil reserves in the Middle East, applied to join BRICS in June as part of its efforts to strengthen economic and political ties with non-Western powers.

“Iran’s cooperation with BRICS has mutual benefits,” the foreign ministry spokesman, Nasser Kanaani, said on Monday.

But the country has stayed afloat by selling discounted oil to China, among other maneuvers. It has also diversified its economy away from oil and increased trade with BRICS members, with a 14 percent increase in non-oil trade in the 2022-23 fiscal year valued at $38.43 billion, according to Iranian news reports that cited customs data.

Politically, Iran would value BRICS membership as an indication that the West’s attempts to isolate it have failed, cementing its role as a regional power and member of a club that sees itself as an alternative to the Western-dominated order.

Iran’s president, Ebrahim Raisi, will travel to the BRICS summit on Wednesday after receiving an invitation to attend, the Iranian state media reported.

Both China and India have long pushed for Indonesia to join BRICS. The Southeast Asian nation is the world’s fourth most populous, with around 280 million people, and already belongs to the Group of 20.

Indonesia’s deputy trade minister, Jerry Sambuaga, told reporters last week that joining BRICS could bring trade opportunities in South America and Africa.

“The interest is there, the potential is clear and the opportunity is up for grabs,” he said.

Indonesia’s president, Joko Widodo, has long advocated a global order that includes developing countries. Last year Indonesian exports to BRICS states amounted to $93.2 billion.

Access to the BRICS bank might aid Mr. Joko’s ambitious infrastructure plans, which include a new capital in Borneo.

But he is likely to be cautious about appearing to take sides.

Though Indonesia’s economic ties with China far surpass those with the United States, the country describes its foreign policy as “free and active” and relies on Western economic cooperation and military supplies.

Egypt is one of the top recipients of American aid, but it has long maintained a strong relationship with Russia and has growing trade ties with China.

Its interest in weaning itself off American dependence strengthened over the last year and a half, as Egypt has learned just how troublesome relying on the dollar can be. Russia’s invasion of Ukraine touched off a foreign currency crisis and then an economic tailspin. Investors pulled billions of dollars out of Egypt in a panic, and crucial wheat and fuel imports, bought with dollars, soared in price. Some imports became scarce and prices rose.

The dollar shortage also made it harder for the country to repay its debts and forced it to devalue its currency steeply, worsening the pain for ordinary Egyptians.

Inside BRICS, Egypt could trade in local currency, which it is already attempting through bilateral deals. It also hopes to attract more investment from member countries, which could in turn bring more money from the United States as it seeks to retain its influence.

Playing both sides has tended to benefit Egypt. Russia is building Egypt’s first nuclear power plant, and China is building part of its new capital. Fear of losing influence has made Western governments reluctant to cut ties over rights abuses or other issues.

“Egypt has good relations with the United States and the West, as well as good relations with the East,” President Abdel Fattah el-Sisi said Sunday. “If the current balance continues, we will be able to join the BRICS economic bloc.”

With Africa’s second-largest economy, Egypt stands a strong chance of being admitted. It has already joined the BRICS bank and has strong or growing trade or political relationships with members.

Paulo Motoryn contributed reporting from Brasília.