The U.S. Treasury Department on Thursday said it was analyzing a report that found World Bank leaders, including former-CEO Kristalina Georgieva, pressured staff to boost China's ranking in the bank's "Doing Business 2018" at a time when they were counting on China to support the bank's capital increase.

"These are serious findings and Treasury is analyzing the report. Our primary responsibility is to uphold the integrity of international financial institutions," spokeswoman Alexandra LaManna said, when asked about a report by law firm WilmerHale about its independent investigation of the matter.

Georgieva, now managing director of the International Monetary Fund, said in a statement she rejected the findings of the report.