In the 2009 Copenhagen climate accord, 21 developed nations and the European Union agreed to provide $30 billion over three years to help poorer nations adapt to climate change and reduce their greenhouse gas emissions.

But nearly two years later, tracking these “fast start” pledges — and what specific programs the funds have been used for — has proved difficult, according to a new report from the World Resources Institute.

The WRI report concludes that “most developed countries are making tentative progress toward delivering” pledged funds. But the group urged more detailed reporting of how the funds were being spent.

The group also expressed concern that cuts in foreign aid in Japan and the United States could affect the agreement.

The nonprofit environmental group warns that a continued lack of transparency from the developed nations will hurt the chances for a deeper global climate agreement.

“The developing countries are seeking satisfaction from fast-start financing before going further in negotiations,” said Clifford Polycarp, a senior associate at WRI.

In 2010, U.S. climate assistance included efforts to boost clean energy, prevent deforestation and otherwise prepare developing nations for climate change. The United States spent $1.7 billion on global climate programs in fiscal 2010, according to the State Department. But the amount offered by the United States in the recently enacted 2011 budget is murky, according to WRI. “We haven’t been able to make sense of the numbers,” Polycarp said.

Another environmental group, the Natural Resources Defense Council, estimates that the 2011 budget includes $750 million to $950 million for foreign climate assistance, “depending on how you count,” said NRDC’s Jake Schmidt.

During climate negotiations in Cancun, Mexico, last year, the developed nations agreed to report their funding commitments each May. But 20 days into the month, WRI was unable to determine how much funding had been committed for 2011 by all but two of the developed countries, Iceland and Australia.

In 2009, the United States originally said it would pay its “fair share” but did not commit to a specific figure, Polycarp said.

The State Department, which handles most foreign climate assistance, has not announced how much it will spend on the fast start agreement in 2011 and did not immediately respond to a request for those figures. The top U.S. climate negotiator, the State Department’s Todd Stern, was unavailable for an interview Friday morning.