Just a day after U.S. President Barack Obama gathered leaders from Southeast Asian countries in California, a U.S. official announced that the Pentagon discovered two HQ-9 missile batteries that were recently deployed on Woody Island in the Paracel chain, one of the areas that are contested in the South China Sea, according to The New York Times.

The missile batteries allegedly have a range of about 125 miles and are capable of destroying aircraft, as well as cruise and ballistic missiles. Though Woody Island has been occupied by Chinese military for the past few decades, countries which also have a claim in the area find the timing of the additional missiles quite suspicious.

Kenneth G. Lieberthal, a senior fellow at the Brookings Institution, stated that China's recent military decisions are putting the region more at risk, especially since countries claiming parts of the disputed areas in the South China Sea, such as the Philippines and Vietnam, are clamoring for international action regarding the issue, reports The Economic Times.

"What China is doing is worrisome because they're obviously increasing their capacity for surveillance and for sustaining a presence that is well beyond what they've had before," he said.

In an announcement on Wednesday, U.S. Secretary of State John Kerry stated that he is expecting to have "very serious" talks with China about the militarization of the disputed islands in the South China Sea, reports Reuters.

"There is every evidence, every day that there has been an increase of militarization of one kind or another. We have had these conversations with the Chinese and I am confident that over the next days we will have further very serious conversation on this," he said.