China spent $240 billion bailing out 22 developing countries between 2008 and 2021, with the amount soaring in recent years as more have struggled to repay loans spent building "Belt & Road" infrastructure, according to a study published Tuesday.

Almost 80% of the rescue lending was made between 2016 and 2021, mainly to middle-income countries including Argentina, Mongolia and Pakistan, according to the report by researchers from the World Bank, Harvard Kennedy School, AidData and the Kiel Institute for the World Economy.

China has lent hundreds of billions of dollars to build infrastructure in developing countries, but lending has tailed off since 2016 as many projects have failed to pay the expected financial dividends.