The United States, Australian, and Japanese foreign ministers called Monday for a halt to land reclamation and military actions in the South China Sea and compliance with an arbitration ruling that invalidated China's vast claims to the disputed waters.
US Secretary of State Rex Tillerson, Australian Foreign Minister Julie Bishop, and Japan's new top diplomat, Taro Kono, also called on their Southeast Asian counterparts to rapidly negotiate a legally binding maritime code with China aimed at preventing an escalation of conflicts in one of the world's busiest waterways.
In a joint statement, the three expressed serious concerns over the long-seething sea disputes and "voiced their strong opposition to coercive unilateral actions that could alter the status quo and increase tensions."
They urged rival claimant states in the South China Sea "to refrain from land reclamation, construction of outposts, militarization of disputed features, and undertaking unilateral actions that cause permanent physical change to the marine environment in areas pending delimitation."
The contending states should clarify their claims peacefully in accordance with a 1982 maritime treaty and international law, according to the three, who met on the sidelines of annual meetings of Asia-Pacific foreign ministers in Manila, including those from China and Russia.
Their remarks, which are aimed at taming aggression in the disputed waters, are considerably stronger than a joint statement of concern issued by their counterparts in the Association of Southeast Asian Nations, a 10-nation bloc whose economies depend heavily on China.
Their stance also contrasts with that of China, which opposes what it considers meddling in Asian disputes by the US and other Western governments. Beijing wants the disputes to be resolved through one-on-one negotiations.
China's territorial disputes in the strategic and potentially oil- and gas-rich waterway with Taiwan and ASEAN member states Brunei, Malaysia, the Philippines, and Vietnam intensified after Beijing built islands in the disputed waters in recent years and reportedly started to install a missile defense system on them, alarming rival claimant states as well as the US and other Western governments.
China's foreign minister said over the weekend that talks for a long-sought code of conduct in the South China Sea, first mooted in 2002, may finally start this year if "outside parties" don't cause a major disruption.
Adding to the drumbeat of criticism, the commander of US forces in the Pacific, Adm. Harry Harris, said Monday that the code of conduct negotiations with an "aggressive" China will be a key challenge for the region.
China's rejection of an international ruling in 2016 that supported the territorial claims of the Philippines "demonstrates to any observer what kind of country China is," Mr. Harris said in Jakarta, the Indonesian capital, at a meeting of the US-Indonesia Friendship Society.
"Continuing claims that are in conflict with other countries will demonstrate to all of us what kind of country China will be," he said.
But Harris offered nothing more than moral support to Southeast Asia.
The region itself is not a treaty partner of the US and it's up to the 10 Southeast Asian countries to respond firmly to China's posture in the South China Sea, he said.
While China has had robust economic ties with Southeast Asia, a diverse region of more than 600 million people with a combined GDP of $2.4 trillion, both have tangled for years over the territorial conflicts. Tensions flared alarmingly in recent years over China's island-building works in one of the most-contested regions, where US naval and aerial "freedom of navigation" patrols have challenged Beijing's claims.
The ministers from the three Asia-Pacific powers "reiterated that the three countries will continue to fly, sail, and operate wherever international law allows."
Disagreement partly over whether to include criticism, even indirectly, of China's increasingly assertive moves in the contested territories delayed the issuance of a joint communique of ASEAN foreign ministers after they held their annual meetings on Saturday in Manila.
When the communique was issued later, the ASEAN ministers surprisingly defied China's stance with indirect criticism of Beijing's land reclamation and military fortifications in the disputed waters.
They also mentioned in their statement a vague reference to an international arbitration ruling last year that invalidated China's historical claims to virtually all of the strategic waterway. As in past criticisms, they did not cite China by name.
This story was reported by The Associated Press