It was a measure of how little was agreed upon that at a dinner on Thursday night, at the end of meetings, the Chinese and Americans spent much of their time praising their cooperation on a single project: Building a Chinese garden at the national arboretum.

Still, the concerns did not seem to hamper progress on economic matters. American businesses face significant hurdles in investing in China — when they are allowed to invest at all. A bilateral treaty might open the door for American financial, consulting and energy companies to make significant inroads in the Chinese market, which is still growing as the number of consumers expands, if not as quickly as in the past.

Business groups applauded the news about the treaty negotiations. Rob Nichols, president of the Financial Services Forum, a lobbying group in Washington, called it a “significant and welcome step forward for the economic relationship between the United States and China.”

“If the two countries are able to reach an agreement for the United States to gain market access to China’s economy — especially in the financial services sector — it would be a win-win for both countries, businesses and workers.”

The two nations would be able to exempt certain industries, like defense, from a bilateral treaty.

Vice Premier Wang Yang of China said through an interpreter that the United States had “pledged to treat Chinese investment equally and fairly” and would welcome investment from Chinese sovereign wealth funds.

Chinese and American officials also announced a series of bilateral initiatives devised to cut emissions that are a cause of climate change. The moves represent something of a softening of views by the United States and China, the world’s two largest producers of such emissions. The two countries have often been antagonists at international climate change meetings.

But Washington and Beijing agreed this week to work together to reduce emissions of soot and carbon dioxide from heavy vehicles, cut energy use in buildings and factories, publish accurate and timely information on emissions, and promote more efficient energy transmission systems. Officials also said they would work together to find ways to trap, store and reuse carbon emissions from power plants that use fossil fuels.