BEIJING (Reuters) - China and Southeast Asian countries agreed on Thursday to a framework for a long-mooted code of conduct for the disputed South China Sea, China’s foreign ministry said, as both sides step up efforts to ease tension in the strategic waterway.

An aerial view of uninhabited island of Spratlys in the disputed South China Sea, April 21, 2017. REUTERS/Erik De Castro

China and the members of the Association of South East Asian Nations (ASEAN) had been hoping to agree on the framework this year, 15 years after committing to draft it.

After a meeting between Chinese and ASEAN officials in the Chinese city of Guiyang, China’s foreign ministry said the framework had been agreed upon, but gave no details of its contents.

It said the talks had been candid and deep and made positive achievements.

All parties “uphold using the framework of regional rules to manage and control disputes, to deepen practical maritime cooperation, to promote consultation on the code and jointly maintain the peace and stability of the South China Sea,” China’s foreign ministry said.

The permanent secretary of Singapore’s foreign ministry, Chee Wee Kiong, said that what he called a “draft” framework would be submitted to a meeting of the foreign ministers of China and the ASEAN states in August in the Philippines.

“We hope to continue the positive momentum of consultation and make steady progress toward a substantive CoC based on consensus as directed by our leaders,” Chee said, in remarks also shown on Chinese state television.

Chinese Vice Foreign Minister Liu Zhenmin, in comments carried on state television, said the framework was comprehensive and took into account the concerns of all sides.

But he called on others to stay out, apparently a coded message to the United States.

“We hope that our consultations on the code are not subject to any outside interference,” Liu said.

The U.S. State Department said it understood ASEAN and China had “not agreed on a text of a Code of Conduct, but on an initial framework describing how such a document might be structured”.

“As we have not seen that text, we would not be in a position to comment on it,” a spokeswoman, Anna Richey-Allen, said.

She said the United States had been calling for “an effective and meaningful” code of conduct compatible with international law, in particular the Law of the Sea Convention.

Some ASEAN diplomats have expressed concern about whether China is being sincere, or whether ASEAN has enough leverage to get China to commit to a set of rules.

Some Southeast Asian countries, including Vietnam and the Philippines, as well as the United States, have expressed concern at what they see as China’s militarization of the South China Sea, including building air strips on man-made islands.

China claims almost the entire South China Sea, through which about $5 trillion in goods pass every year. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.