Two dozen of the world's richest nations, including the United States and Japan, are pulling back from their global development push, a study published on Thursday, shows, with many slashing aid budgets and cash funnelled through multilateral lenders.

The Commitment to Development Index ranks 38 major economies across more than 100 data points to assess how their policies affect poorer nations across development finance, investment, migration, trade, environment and health as well as security and technology.

Sweden, Germany, Norway and Finland kept their place at the top of the list, which is compiled and published by Washington-based think tank Center for Global Development every two years.

The United Kingdom gained two places to become number 5 in the latest ranking. That was based on data prior to the government announcing its 40 percent aid cut, which is expected to see the country slide lower again in future index estimates.

Meanwhile, the United States fell two places to number 28 in the ranking in this latest report; however, this did not reflect the billions of dollars in cuts in aid announced since Donald Trump became president.

"The changes the Trump administration is making are very significant," said Ian Mitchell, a senior policy fellow at the CGD, predicting a further slide ahead.

The ranking is being published as South Africa is gearing up to host leaders of the Group of 20 major economies this weekend where it will also hand over its presidency to the United States.

Trump, who has slashed the U.S. foreign aid budget and shuttered USAID earlier this year, will not attend the first G20 summit in Africa. Aid and development financing has been cut by many developed economies in favour of defence spending.

There were some bright spots in the index, said Mitchell.

More than three-quarters of countries were cutting their emissions between 2019-2023, the research found, even though a rise in China lifted the overall level. More countries were hosting migrants and refugees, he added.

"While some improved on migration or environment, overall the trend is backward with arms exports, trade barriers and fossil fuel subsidies all rising," CGD said.

REUTERS

World's richest nations are pulling back from global development efforts, study shows