US President Barack Obama on Monday weighed in on territorial disputes in the South China Sea, urging regional powers, particularly China, to respect the law and stop "throwing elbows."

As several Asian regional powers face off over maritime borders, Obama warned about disregard for existing laws and a move away from established ways of resolving disputes.

"If you start losing that approach, and suddenly conflicts arise and claims are made based on how big the country is or how powerful its navy is instead of based on law, then I think Asia will be less prosperous and the Pacific region will be less prosperous," he said.

The United States does not hold any territorial claims in the South China Sea, Obama added. But as a "Pacific power" Washington has vocally called on China and other nations to end reclamation.

His administration has vowed to continue sending military aircraft and ships to the tense region to protect navigation rights.

"We think that land reclamation, aggressive actions by any party in that area are counterproductive," said Obama.

Turning to China directly, Obama adopted a boxing metaphor, saying "it may be that some of their claims are legitimate, but they shouldn't just try to establish that based on throwing elbows and pushing people out of the way."