• Yulin Naval Base has been converted into a base for nuclear submarines
  • China claims 90% of the disputed South China Sea
  • The U.S. imposed sanctions on Chinese officials 

China has expanded the capabilities of a submarine base, which acts as a hub of its operations in the South China Sea, raising the hackles of its maritime neighbors and the United States, which wants to check increased Chinese assertiveness in the international waters.

The Yulin Naval Base on the Hainan Island has been converted from a conventional submarine facility into a base for nuclear submarines, Voice of America reported, quoting analysts at

The naval base can accommodate 16 submarines, according to the report. The analysts said aircraft carriers and remote-sensing equipment are also expected to be based at the base.

Beijing also plans to build a tunnel linking Hainan to mainland China. An adviser to the Chinese government has called for the revival of a plan to build the tunnel, The South China Morning Post reported.

Wu Shicun, head of the National Institute for South China Sea Studies, told SCMP that a cross-sea passage project should be added to China’s current or next five-year plan. He said that such a tunnel could shorten the travel time to Hainan and give a fillip to the island's economy.

China's claim over 90 percent of the South China Sea has been a constant cause of friction with Brunei, Malaysia, the Philippines, Taiwan and Vietnam. The United States has rejected China’s claims to offshore resources across most of the South China Sea, calling them “completely unlawful," and imposed new sanctions on Chinese officials.

The Trump administration last year sanctioned 24 Chinese companies for helping China build artificial islands in the South China Sea. Fresh sanctions were imposed last week on Chinese officials.

The U.S. Department of State said it was imposing visa restrictions on those “responsible for, or complicit in, either the large-scale reclamation, construction, or militarization of disputed outposts in the South China Sea, or the PRC’s use of coercion against Southeast Asian claimants to inhibit their access to offshore resources in the South China Sea.”

China has been accused of aggressively expanding its territorial claims and increasing activities in the South China Sea. A Vietnamese fishing boat was rammed and sunk by a Chinese maritime vessel last year, forcing Vietnam to lodge an official protest with Beijing. China also reportedly built two research stations on the territory claimed by the Philippines.

Beijing claims the majority of the resource-rich South China Sea
Beijing claims the majority of the resource-rich South China Sea AFP / Ted ALJIBE