A satellite image acquired by a private company on Feb. 14 shows what Western officials believe are Chinese HQ-9 surface-to-air defense missiles on the disputed Woody Island in the South China Sea. (ImageSat International)

The United States is very concerned about China’s growing militarization of the South China Sea and intends to have a “very serious conversation” with Beijing after reports emerged that it had deployed suspected ­surface-to-air missile batteries on a disputed island, Secretary of State John F. Kerry said Wednesday.

“There is every evidence, every day that there has been an increase of militarization of one kind or another,” Kerry told reporters when asked about the reported deployment, agencies reported. “It’s of serious concern.”

“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,” Kerry said.

Satellite images apparently showing the missile sites were released as President Obama wrapped up a summit with leaders from nations making rival maritime claims in the region. The report has heightened concern not just in the United States but also in Asia about Beijing’s expanding ambitions in the region.

Taiwan’s Ministry of National Defense said in a statement it “grasped that Communist China had deployed” missiles on Woody Island in the Paracel chain and urged “relevant parties to refrain from any unilateral measure that would increase tensions.”

Photos: New satellite imagery of Chinese island-building

Taiwan’s statement followed a report on Fox News on Tuesday that was based on satellite images acquired by a private company. Navy Cmdr. Bill Urban, a Pentagon spokesman, said Wednesday evening that the photos supported reports of a deployment.

“Commercial imagery indicates that China has deployed a surface-to-air missile system on a disputed outpost in the South China Sea,” Urban said. “We are concerned that these actions are increasing tensions in the region and are counterproductive.”

The Paracel Islands have been under Chinese control for more than 40 years but are also claimed by Taiwan and Vietnam. The reported Chinese move followed a U.S. naval operation in which a missile destroyer sailed close to another island in the Paracels last month.

The South China Sea, bordered by China and a number of Southeast Asian nations, including the Philippines, has been the center of rising tensions since Beijing began expanding its foothold in the region last year.

China has built seven artificial islands in the Spratly chain in the South China Sea and constructed airstrips on three of them, prompting worry in the West about possible military intent. But China argues that other nations in the region have also built airstrips and reclaimed land.

At a news conference Wednesday, China’s foreign minister, Wang Yi, said he had only just been told of the reports but suggested they were an attempt by “certain Western media to create news stories.”

He also drew attention to lighthouses, meteorological stations, and shelter and rescue facilities that China has built on some islands.

“As for the limited and necessary self-defense facilities China has built on islands and reefs stationed by Chinese personnel, that is consistent with the self defense and self-preservation China is entitled to under international law,” he said. Wang added that “nonmilitarization is certainly in the interest of all parties, but nonmilitarization should not be just about one single country.”

During a state visit to the United States in September, Chinese leader Xi Jinping pledged not to militarize the contested Spratly Islands, which lie to the south of the Paracels. On Wednesday, Kerry reiterated that the nonmilitarization standard in the South China Sea should be applied to all countries.

Fox News, showing civilian satellite images from ImageSat International, said two batteries of eight surface-to-air missile launchers, as well as a radar system, were deployed on Woody Island at some point between Feb. 3 and Sunday.

Urban, the Pentagon spokesman, said the images appeared to show an HQ-9 air defense system; HQ-9s have a range of about 125 miles.

Adm. Harry B. Harris Jr., head of the U.S. Pacific Command, said the deployment of missiles to the Paracels would not be a surprise but would be a concern and would contradict China’s pledge not to militarize the region, Reuters reported. “We will conduct more, and more complex, freedom-of-navigation operations as time goes on in the South China Sea,” Harris said at a briefing in Tokyo. “We have no intention of stopping.”

Woody Island, called Yongxingdao by China, boasts an artificial harbor, an airport, roads, army posts and other buildings.

Recent satellite imagery appears to show that China is conducting dredging and landfilling operations at two other islands in the Paracels, while adding a helicopter base on Duncan Island that could be used for anti-submarine warfare missions, the Diplomat magazine reported last week.

The news broke just as Obama was completing two days of talks with 10 leaders of the Association of Southeast Asian Nations, or ASEAN, at the Sunnylands retreat in California.

Among those present were the leaders of Vietnam, Brunei, Malaysia and the Philippines, which all have overlapping claims with China for various islands, reefs and atolls in parts of the South China Sea. “We discussed the need for tangible steps in the South China Sea to lower tensions, including a halt to further reclamation, new construction and militarization of disputed areas,” Obama said at a Tuesday news conference.

At Sunnylands, Obama also pledged that the United States would continue to conduct “freedom of navigation” exercises in the South China Sea. He said maritime disputes must be resolved by legal means, including through a case brought by the Philippines challenging China’s claims over vast swaths of that sea.

The White House also announced that Obama has accepted an invitation to visit Vietnam in May, reflecting a growing rapport between Washington and Hanoi that irks Beijing.

China has accused the United States of undermining peace and stability in the region and infringing on its sovereignty by sailing naval vessels near some of the disputed islands in the South China Sea. Last month, a U.S. guided-missile destroyer passed close to Triton Island in the Paracels in what the U.S. military said was a response to “excessive maritime claims” that impinge on the rights and freedoms of the United States and other nations. China said the action “severely violated the law.”

Beijing has also refused to take part in an arbitration case brought by the Philippines in The Hague, arguing that the two countries should settle their dispute bilaterally. But Obama said all parties to the U.N. law of the sea are obligated to respect the ruling.

Ian Storey, a senior fellow at the Institute of Southeast Asian Studies in Singapore, said China has been building up its military facilities on the Paracels for some years.

He said that it was unclear whether this latest reported move was a direct reaction to the recent U.S. naval operation in Paracels but that Beijing would probably try to justify it as a “reaction to U.S. military moves in the South China Sea.”

It could, he said, be a precursor to China eventually declaring some kind of air defense identification zone in the northern South China Sea, which could ultimately be extended farther south as military facilities are built up on the Spratly Islands.

Such a move would be seen very negatively by the United States and regional claimants. But for the time being, deploying missiles on Woody Island is less provocative than making a similar move on the Spratlys, he said, because the Paracels are basically a bilateral issue with Vietnam rather than a multilateral one.

“It is not as provocative as it could have been,” he said. “If they had deployed missiles on the Spratlys, that would have elicited a much stronger response from other countries in Southeast Asia. We’ll see a strong reaction from Vietnam, but I don't anticipate the other claimants will react strongly, if at all.”

Taiwan’s president-elect, Tsai Ing-wen, told reporters following news of the report that tensions were higher in the region, according to Taiwan’s state-owned Central News Agency. “We urge all parties to work on the situation based on principles of peaceful solution and self-control,” Tsai said.

Philippine Defense Secretary Voltaire Gazmin said the deployment of missiles on Woody Island “increases tensions in the South China Sea,” the Associated Press reported.

In Vietnam, about 100 people, gathering to commemorate the start of a 1979 invasion by Chinese forces, chanted “Down with the aggressors” and “Hoang Sa, Truong Sa,” the Vietnamese terms for the Paracel and Spratly island chains.

Karen DeYoung and Dan Lamothe in Washington contributed to this report.

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