The United States called on China and other rival claimants Wednesday to exercise restraint when an international tribunal issues a landmark ruling on the South China Sea disputes that Beijing has chosen to ignore.

A senior U.S. State Department official, who spoke on condition of anonymity to Asian journalists through a teleconference, said the upcoming decision by the arbitration panel in The Hague may offer "a great deal of clarity" on the disputes and help the claimants forge an arrangement to avoid potential confrontations.

She said the decision, expected within weeks, could also serve as a jumping off point to diplomatic talks.

"We would certainly call on all governments to exercise restraint and to use this post-arbitration period as an opportunity to restart those diplomatic discussions," she said.

China has said it would not recognize any arbitration decision despite calls by several Asian and Western governments for it to respect international law. Some fear Beijing may take a harder stance and take provocative actions if it comes under pressure from outside, including by the United States, to comply with an adversarial ruling.

In a harsh attack on U.S. policies in Asia, the flagship newspaper of China's ruling Communist Party on Wednesday accused Washington of seeking to turn the South China Sea "into a powder keg" and warned it not to underestimate China's determination to defend its territorial claims.

The People's Daily cited recent combined exercises by two Navy aircraft carrier strike groups off the coast of the Philippines as a sign of U.S. hegemony and said Washington has made a mistake in seeking to intimidateChina.

In making displays of military power aimed at China, the U.S. has "picked the wrong counterpart," said the editorial, the contents of which are usually vetted by high ranking party officials.

U.S. military activity, including freedom of navigation cruises near China's man-made islands and exercises with allies, is contributing to the militarization of the region, the editorial said.

Beijing prefers one-on-one negotiations with each of the rival claimants, an arrangement that gives it advantage because of its sheer size and clout and prevents Washington from playing any role to resolve the conflicts.

In the 2013 case, the Philippines challenged the validity of China's so-called nine-dash line claiming virtually the entire stretch of the South China Sea, a crucial waterway where a major chunk of the world's oil and trade passes. The Philippines also asked the tribunal to rule whether several disputed areas are outcrops, reefs or islands and how much stretch of territorial waters they project.

The U.S. official also expressed concern over China's coast guard ships escorting Chinese fishing vessels in areas including Indonesia's Natuna Islands, where Indonesian vessels fired warning shots.