US Secretary of State John Kerry is expected to press countries conducting drilling and other activities in the South China Sea to pause all projects.
The freeze will be voluntary and will be proposed at a meeting this weekend with the Association of Southeast Asian Nations (ASEAN).
Chinese officials said they have a historical claim on the South China Sea and won’t take part in a voluntary freeze, AP said Wednesday.
China hasn’t been receptive to such requests in the past.
The South China Sea has become a site of contentious territory claims by nations in Southeast Asia.
China, Philippines, Vietnam, Malaysia, Taiwan and Brunei all have rival claims on territory in the sea.
China has claimed about 90 percent of it.
The US Energy Information Administration estimated proved and probable reserves in the South China Sea to be approximately 11 billion barrels of oil and 190 trillion cubic feet of natural gas.
About $5 trillion of maritime trade passes through the South China Sea annually.
Chinese drilling activities in contested waters have stoked tensions between it and other ASEAN members.
In July, China’s state-owned oil company CNPC pulled a deep-sea rig out of the Paracel Islands, an area claimed by both China and Vietnam, after the project placed tension on China-Vietnam relations.
The top US diplomat in Asia Daniel Russel said Kerry will support a code of conduct and said all claimants could do more to clarify their territories in accordance with international law, Reuters said.