China can't pick and choose principles to benefit from: Ashton Carter

Washington: China cannot "pick and choose" principles it wants to benefit from and those it prefers to try to undercut, US Defence Secretary Ashton Carter has said amid flexing of muscles by Beijing in the disputed South China Sea.

Noting that the US has "serious concerns" over China's recent actions including in the seas, Carter said principles are meant to apply to every nation "equally".

"The United States still has serious concerns with some of China's recent actions on the seas, in cyberspace, and elsewhere. Beijing sometimes appears to want to pick and choose which principles it wants to benefit from and which it prefers to try to undercut," he said in his remarks aboard the USS Carl Vinson in San Diego yesterday.

For example, the universal right to freedom of navigation that allows China's ships and aircraft to transit safely and peacefully is the same right that Beijing criticises other countries for exercising in the region. "But principles are not like that. They're meant to apply to everyone, and every nation, equally," he argued.

China is involved in a raging dispute with the Philippines, Vietnam, Taiwan, Malaysia and Brunei over ownership of territory in the South China Sea (SCS), a busy waterway through which India's 50 percent trade passes.

The US has said it committed to the principle of the freedom of navigation in the strategic waters.

Carter said given America's inclusive approach, the Department of Defence is taking steps to modernise its military-to-military relationship with China.

"As President (Barack) Obama has said, the US-China relationship will have elements of cooperation but also competition. We hope that China chooses to join the rest of the region in strengthening and upholding the shared principles that have helped so many nations around the region, including China, to rise and prosper," Carter said.

He noted that Asia-Pacific is the most consequential region for America's future.

"We're managing historic change in the Asia-Pacific... where China is rising, which is fine, but behaving aggressively, which is not. We're strengthening our deterrent and defence forces in the face of North Korea's continued nuclear and missile provocations," he said.

"We're checking Iranian aggression and malign influence in the Gulf, and protecting our friends and allies in the Middle East. And we're accelerating the certain defeat of ISIL... In its parent tumour in Iraq and Syria, and everywhere it metastasizes around the world, even as we're helping protect our people here in the homeland," he said.

He added that today the US armed forces are countering the prospect of Russian aggression and coercion, especially in Europe.