The books confirm the fact that Hoang Sa and Truong Sa have been under management and protection by Vietnam for generations.

Vietnam has friendly and cooperative relationships with China but Vietnam would not allow anybody to do anything that violates its sovereignty and territorial integrity.

The intrusion takes places after a Chinese survey vessel and escorts violated Vietnamese waters for almost three months last year.

China's move undermines negotiations among China and ASEAN member states for a binding Code of Conduct in the South China Sea (CoC).

Hanoi said all maritime territorial claims inconsistent with UNCLOS are null and void.