"(We) must resolutely safeguard China's national sovereignty, maritime rights and other core interests," said Chief Justice Zhou Qiang on Sunday during the ongoing annual meeting of China's parliament, BBC News reports.
Beijing is locked in disputes with its neighbours over claims in the resource-rich South China Sea, with tensions raised in recent months over China's aggressive land reclamation.
It has also squared off with Japan over the Diaoyu or Senkaku islands.
Read alsoU.S. sends carrier strike group to South China SeaChina claims a large swath of the South and East China Sea, creating multiple overlaps with areas claimed by the Philippines, Vietnam, Brunei, Malaysia, Taiwan and Japan.
The Philippines currently has a case lodged against China at the UN's Permanent Court of Arbitration in The Hague.
It says the "nine-dash line", which China uses to demarcate its claims, is unlawful under the UN Convention on the Law of the Sea, which both countries have signed.
Beijing has refused to participate in the tribunal, saying the court has no power to rule on the matter.
Tensions have increased as China continues to build artificial islands, airport runways and facilities on disputed reefs, prompting calls from the US for a halt in such activities.
Opponents have accused Beijing of militarisation but China says such construction is within its rights and any building is for civilian purposes.