The think tank stressed that its research has made clear China needs to improve its debt practices soon.
Currently, China is listed as an ad hoc participant of the Paris Club, a collection of creditor nations. The Paris Club's 22 permanent members, which do not include China, conduct negotiations with debtor countries that have difficulties repaying loans.
While the study acknowledged that on the whole, the initiative was "unlikely to cause a systemic debt problem," it still "significantly increased (the) risk of a sovereign debt default" in a number of countries, most of which were small and relatively poor.
"Belt and Road provides something that countries desperately want — financing for infrastructure. But when it comes to this type of lending, there can be too much of a good thing," John Hurley, one of the report's authors and a visiting fellow at the Center for Global Development, said in a statement.
Others have also acknowledged issues related to China's financing practices, but came across as more upbeat.
"There are certainly things to worry about, such as growing indebtedness of some of China's big clients ... But there are signs of evolution," David Dollar, senior fellow at the Brookings Institution, wrote in a conference paper presented in October.