(Bloomberg) — China asserted the right to maintain security over islands it’s building in the South China Sea, after the country’s navy ordered a U.S. surveillance plane to leave the area.

Foreign Ministry spokesman Hong Lei said Thursday that China has sovereignty over the artificial islands it’s created through land reclamation in the Spratly chain. The country is “entitled to the surveillance over related airspace and sea areas so as to prevent maritime and airspace accidents and situations that could harm China’s national security,” Hong said at a news briefing in Beijing.

The Chinese navy issued eight warnings Wednesday to a U.S. P8-A Poseidon conducting surveillance flights over the islands, according to the CNN, which was aboard the plane. A radio message received by the U.S. plane said: “This is Chinese navy. You are approaching our military alert zone. Leave immediately.” The P8 crew responded that the aircraft was flying through international airspace, the report said.

While saying he had no details about the exchange, Hong called on countries “to respect China’s sovereignty over the South China Sea and avoid actions that may complicate and intensify controversies.”

Read more: http://gcaptain.com/china-and-u-s-navy-have-had-two-confrontations-in-south-china-sea-this-week/