SINGAPORE/BEIJING -- China wants to prohibit oil exploration in the South China Sea by countries from outside the region as part of a long-delayed code of conduct for the waters, sources familiar with the matter said.
Beijing's proposal, which is holding up negotiations on the rules with Southeast Asian nations, appears meant to stop oil surveys from becoming footholds for greater U.S. influence in the strategically important body of water.
China inserted language on the oil exploration ban into a working document proposal this August, according to people close to the negotiations. Officials from the Association of Southeast Asian Nations side have called for the language's removal, saying it conflicts with international maritime law.
But the bloc presents far from a united front on South China Sea issues, with some members, notably Cambodia and Laos, leaning closer to Beijing's views. The proposed code of conduct is expected to be discussed at this month's East Asia Summit in Singapore.
China and ASEAN have been discussing changes to a 2002 declaration on the peaceful resolution of disputes in the South China Sea that would give the rules legal force. As it stands, the declaration is merely aspirational and has proved unable to stop Chinese island-building in the waters.
South China Sea nations including China, Vietnam and the Philippines seek opportunities to develop the plentiful reserves of energy that the sea is thought to hold. But apart from China, they lack well-developed oil industries and need to rely on foreign technology.
Beijing worries that the U.S. could try to use joint oil development projects with ASEAN countries to gain a greater presence in the sea.
Some observers suspect that China proposed the language knowing that ASEAN members would not accept, with the intention of delaying the code of conduct while Beijing's power in the South China Sea grows.
The South China Sea's lack of clear maritime boundaries makes it a difficult place to ban oil exploration by outside countries, according to a specialist in international law.
As part of the code of conduct, China has also proposed barring outside countries from taking part in joint military exercises with ASEAN countries in the South China Sea. ASEAN members including Singapore have not agreed to this provision, creating another obstacle to concluding the negotiations.
ASEAN is moving to strengthen ties with China, as shown by last month's first-ever joint military exercises. At the same time, the Southeast Asian bloc plans to hold naval exercises with the U.S. as early as next year.