China’s state media and Vietnam’s Foreign Ministry traded harsh words this week. The exchange came after the Vietnamese issued a strong protest over Chinese plans to search for oil in a disputed area of the South China Sea.

It would be the first time that China has moved its massive and mobile deepwater drilling rig into the disputed area.

Both nations have claims over the islands in questions, which Vietnam calls the Paracel and China the Xisha Islands. They waters around them are believed to contain vast quantities of oil and natural gas deposits.

The row came just days after President Barack Obama wrapped up a trip to Asia. Visiting Japan, Malaysia, the Philippines and South Korea, the American leader reaffirmed his country’s commitments to maintaining security in the region. Japan, Malaysia and the Philippines all have disputes with China over islands in the East and South China Seas.

In an editorial in The Global Times, considered a mouthpiece for the ruling Communist Party, there were fiery words directed toward Vietnam. It said the Southeast Asian country lacked will; that it didn’t have “the guts to attack” China’s rig directly. It warned Vietnam that if it became more aggressive, “China should give Hanoi the lesson it deserves.”

China’s Maritime Safety Administration on Monday barred ships from coming within three nautical miles of the oil rig which will be conducting explorations until August.

Vietnam claims the Paracel islands as its own and are within its exclusive economic zone. The Foreign Ministry said China’s action is illegal and that the rig will be operating on Vietnam’s continental shelf within 120 nautical miles off its coast.

Tensions in the area have been steadily rising since China’s assertion of sovereignty over almost the entire South China Sea in 2010. A year later, China warned Vietnam that it would not hesitate to use military force to back up its claims. Since then there have been tit for tat responses by both sides and numerous provocations by Chinese maritime and fishing vessels.

In 2012, Vietnam partnered with Russia’s Gazprom to develop two offshore gasfields in the sea and it has issued a license to ExxonMobil as well.