WASHINGTON (AP) — The U.S. is calling for Asian nations to freeze new construction and establishment of outposts in the disputed South China Sea to lower the risk of a conflict.

The proposal was detailed Friday by senior State Department official Michael Fuchs. He voiced concern over the “increasingly tenuous situation” as an assertive China and five of its smaller neighbors vie for control of tiny islands and reefs in waters with plentiful fisheries and potential hydrocarbon reserves.

Fuchs said no claimant was solely responsible for the tensions, but criticized a pattern of “provocative” behavior by China.

He told a Washington think tank the claimants themselves would need to agree to the terms of the freeze.

Last month, the Philippines proposed a moratorium on construction in the South China Sea. China rejected it.