The US defence chief Saturday described China's activities in the disputed South China Sea as "self-isolating," and warned that it could lead to a "Great Wall of isolation" within the region.
Secretary of Defense Ashton Carter emphasised the "enduring" US presence in the Asia-Pacific, at a time of growing tensions ahead of a ruling from the international tribunal on territorial claims in the South China Sea.
"The US will remain for decades the primary provider of regional security and a leading contributor to the region’s security network," he told the annual Shangri-La Dialogue, highlighting American military capabilities and hardware.
Carter said China's potential land-reclamation activity on the disputed Scarborough Shoal – which the Philippines also claims – would be "provocative and destabilising."
"I hope that this development doesn’t occur, because it will result in action being taken both by the US and by others in the region which will have the effect of increasing tensions, but also isolating China," he said.
Carter insisted that the US was motivated by principle, rather than a specific focus on China, but said Beijing has "by far and away" carried out more land reclamation and militarisation activity in the disputed areas.
Disputes in the South China Sea have long been a concern for regional stability. An international tribunal in the Hague is expected to soon deliver its final decision on the dispute between the Philippines and China.
Carter called on all parties to adhere to the ruling.
"That is a great opportunity for countries of the region to show respect for principle and international law, to avoid self-isolation on the part of any party," he said.
The Shangri-La Dialogue includes defence ministers and military chiefs of 28 Asia-Pacific states to discuss mutual security issues. It takes its name from the Shangri-La Hotel in Singapore, where it has been held each year since 2002.