Washington, D.C. ? U.S. officials have raised a second round of unusually bluntly worded objections to a proposed global warming declaration that Germany prepared for next month’s G-8 summit.

Representatives from the world’s leading industrial nations met Thursday and Friday in Heiligendamm, Germany, to negotiate over German Chancellor Angela Merkel’s proposed statement, which calls for limiting the worldwide temperature rise this century to 3.6 degrees Fahrenheit and cutting global greenhouse gas emissions to 50 percent below 1990 levels by 2050.

Bush administration officials – who raised similar objections in April – rejected the idea of setting mandatory emissions targets as well as language calling for the G-8 nations to raise the overall energy efficiencies of their countries by 20 percent by 2020.

The climate document remains the only unresolved issue in the statements the world leaders are expected to sign at the June 6-8 summit.