The US State Department has expressed concern if more Chinese rigs placed in “disputed waters” in the East Sea.

Spokeswoman Jen Psaki said at a press conference in Washington on June 20 that the US State Department did not have enough information about the placement of the rigs and so would withhold judgment.

"If a rig were placed in disputed waters, that would be a concern," she told reporters.

According to the spokeswoman, the US certainly has “a national interest in the maintenance of peace and stability in the region."

On the same day, addressing after their talks in Washington DC, US President Barack Obama and New Zealand’s Prime Minister John Key stressed the need to peacefully resolve a dispute over China’s stationing of its oil rig in the East Sea and avoid escalating tension.

At the beginning of May 2014, China illegally dispatched its Haiyang Shiyou-981 oil rig as well as a large fleet of armed vessels, military ships and aircraft to Vietnam’s waters and positioned the rig at 15 degrees 29 minutes 58 seconds north latitude and 111 degrees 12 minutes 06 seconds east longitude, 80 miles deep into Vietnam’s continental shelf and exclusive economic zone.

Despite Vietnam’s protest, China expanded its scale of operation and moved the rig to 15 degrees 33 minutes 36 seconds north latitude and 111 degrees 34 minutes 11 seconds east longitude, 60 nautical miles deep inside Vietnam’s continental shelf and exclusive economic zone.

China’s armed vessels have aggressively and consistently fired high-power water cannons at and intentionally rammed against Vietnamese public-service and civil ships, causing damage to many boats and injuring many people on board.

Chinese ships have also continuously encircled, constrained and driven away Vietnamese fishing boats operating normally in its traditional fishing ground near Vietnam’s Hoang Sa (Paracel) Archipelago.-VNA