The clause is largely directed against efforts by U.S. Congress to impose trade penalties on countries that do not commit to specific action against greenhouse gases.
Chief delegate Shyam Saran said such measures looked like "protectionism under a green label," and were complicating the latest round of climate negotiations in Bonn.
Trade issues are "extraneous to what we are trying to construct here, which is a collaborative response to an extraordinary global challenge," Saran told The Associated Press.
The talks in Bonn adjourn Friday after five days of meetings, and resume next month in Bangkok with the aim of reaching a new agreement by the December conference in Copenhagen. The new accord would succeed the 1997 Kyoto Protocol.
Officials at the talks Friday said delegates have made no attempt to settle outstanding differences on key issues, and there has been little progress in whittling down a 200-page draft accord.
The U.S. House or Representatives has passed a climate bill that would impose trade penalties on countries that do not accept limits on their emissions, and the Senate is considering a similar bill. President Barack Obama has opposed attaching trade issues to climate and energy legislation.
The Kyoto accord required 37 industrial countries to reduce greenhouse gas emissions by a total 5.2 percent from 1990 levels by 2012, but made no obligations on developing countries.
The world's wealthier nations want developing countries, such as China and India, to share the burden and agree to slow their explosive emissions growth, even if they cannot yet make reductions.
The developing countries, however, have resisted specific commitments, holding out for pledges of hundreds of billions of dollars to help them adapt to climate conditions and move to low-carbon growth.
Poorer countries also want the wealthy ones to commit to reducing emissions further by up to 40 percent by 2020, from 1990 levels. So far, the wealthier bloc has pledged an aggregate reduction of 15-21 percent, the U.N. Climate Change Secretariat said this week.
Those figures exclude the United States, which rejected the Kyoto Protocol but says it wants to join in a Copenhagen deal. The House bill called for a 17 percent emissions reduction from 2005 and a cut of more than 80 percent by 2050.
Environmental activists warned that progress in the talks was too slow, with just a few weeks of actual negotiating time left before the decisive conference in December.
Unless every country contributes more, the final agreement could become known as "greenwash Copenhagen," said Aileen Yang, the climate campaign manager for Greenpeace China.
In New Delhi, Environment Minister Jairam Ramesh said India "is not yet prepared to take on legal binding targets" regarding its carbon emissions, "but it does not mean that India is not ready to take on responsibilities."
Ramesh, who is heading to China on Aug. 24 for environment talks, said India would control its carbon footprint through measures including the formation of an environmental protection agency modeled on the U.S. Environmental Protection Agency. He said the new Indian agency would likely be in place by December.
Saran said India already is spending 2-2.5 percent of its gross domestic product on adapting to climate change, from introducing new crops to researching the effect of melting glaciers and the need to build reservoirs. India also will spend $2.5 billion over the next five years to regenerate its forests.
