Reforms to major international institutions are set to be at the centre of talks between the foreign ministers of the G20 developed and emerging economies on Thursday.
Institutions like the UN Security Council are under fire, with critics saying they are increasingly irrelevant.
Two years after the Russian attack on Ukraine, the UN Security Council is often blocked in its decisions due to Moscow's veto power.
At the G20 group's meeting in Rio de Janeiro, Brazil, German Foreign Minister Annalena Baerbock said on Wednesday that the modernization of financial institutions was at the top of the G20's agenda.
The countries most affected by the climate crisis pay the highest interest rates, and this "is deeply unfair, and it is also more than counterproductive in terms of economic policy," Baerbock said.
The risk of natural disasters is driving up the financing costs of island states such as Fiji and the Philippines in particular, said Baerbock.
Collectively, the G20 group of developed and emerging economies represents around 80% of the world's economic output and 60% of the world's population.
A reorganization of the international system is one of the declared goals of Brazil's G20 presidency.
President Luiz Inácio Lula da Silva recently criticized the UN Security Council as lacking credibility and accused international financial institutions such as the International Monetary Fund (IMF) and the World Bank of interfering too much in the internal affairs of creditor countries.
Lula sees Brazil as the mouthpiece of the Global South and wants to give the emerging economies a stronger voice.
