China said on Tuesday that the US is the root of “militarization” in the South China Sea, urging it to stop sowing dissension among countries in the region.

“The actions of the US are the root of the so-called militarization in the South China Sea,” the Defense Ministry said in a written response to China Daily, citing increased US military deployment in the region, provocative US reconnaissance of Chinese islands and joint military exercises with allies targeted at China.

“Relevant sides have turned a blind eye to it and repeatedly criticized China’s legitimate construction on islands, intentionally fabricating issues and fueling tensions. It is hyping with hidden intentions.”

The ministry was responding to a US think tank report that, citing satellite imagery, said Beijing is installing radar facilities on Huayang Reef of the Nansha Islands in the South China Sea.

The report by the Washington-based Center for Strategic and International Studies came after US officials said China had deployed a surface-to-air missile system on Yongxing Island of the Xisha Islands.

Washington has voiced concern over what it called China’s “militarization” in the South China Sea, but the Foreign Ministry has said its military deployments there were no different from US defense deployments on Hawaii.

On Tuesday, Foreign Ministry spokeswoman Hua Chun-ying, in response to a senior US naval officer’s call for more naval operations in the region, urged the US to stop sowing dissension among South China Sea countries.

“I must point out that the freedom of navigation in the South China Sea entitled under international law does not mean US naval vessels or airplanes’ freedom to flex their muscle,” Hua said.

Vice-Admiral Joseph Aucoin, commander of the US Navy’s 7th Fleet, said on Monday that Australia and other countries should follow the US lead and conduct “freedom of navigation” naval operations within 12 nautical miles of contested islands in the South China Sea, the Australian Broadcasting Corp reported.

Asked to comment on some US media saying that China is creating a “great wall of sand” in the South China Sea, Hua said China’s sovereignty and claims are grounded in history and upheld by successive Chinese governments. “If the words ‘great wall’ must be used, we suggest those media pay more attention to Chinese people’s ‘great wall of will’ to firmly safeguard territorial sovereignty and legal rights,” she said.