The local government in China's southernmost city has vowed to "delay not a single day" to accelerate the city's construction in the South China Sea.

The local government also said it will put safeguarding national sovereignty in a better position. The pledge by Xiao Jie, mayor of Sansha, was made on the sidelines of the first session of the National People's Congress (NPC), China's top legislature.

Xiao's promise came as Chinese Foreign Minister Yang Jiechi said Wednesday that the central authorities' decision to set up Sansha City last year was an important move after taking into account situations at home and abroad.

Home to about 1,000 residents, Sansha was officially set up as China's youngest city in July last year to administer about 2-million-square-km islands, coastal areas and territorial seas in the South China Sea.

The city of Sansha gets its name from three island groups under its jurisdiction - Xisha, Zhongsha and Nansha - and their surrounding waters in the South China Sea.

Special work teams have been established and local laws and regulations have been passed to accelerate the construction of infrastructure facilities in Sansha City, said Xiao, who is also a deputy to the 12th NPC session.