BEIJING (Reuters) - China "really needs" its defenses in the South China Sea in the face of a militarization process being pushed by the United States, and can deploy whatever equipment it wants on its own soil, China's Defence Ministry said on Thursday.

China and the United States have sparred repeatedly over the past week following reports China is deploying advanced missiles, fighters and radar equipment on islands in the South China Sea, especially on Woody Island in the Paracels.

The United States has accused China of militarizing the disputed waters. Beijing, for its part, has been angered by "freedom of navigation" air and sea patrols the United States has conducted near islands China claims in the South China Sea.

Those have included one by two B-52 strategic bombers in November and by a U.S. Navy destroyer that sailed within 12 nautical miles of Triton Island in the Paracels last month.

"The United States is the real promoter of the militarization of the South China Sea," defense ministry spokesman Wu Qian told a regular monthly news briefing.

"China's construction of military facilities on the islands and reefs of the South China Sea is really needed."

The Paracel Islands are China's "inherent territory", he added.

"It is China's legitimate right to deploy defense facilities within our own territory, no matter in the past or at present, no matter temporarily or permanently, no matter what equipment it is," Wu said.

People are being "dazzled" by the endless hyping up by U.S. media of equipment China is deploying in the South China Sea, he added.

"One minute it's air defense missiles, then radars, then various types of aircraft - who knows what tomorrow will bring in terms of new equipment being hyped up."

Even the Americans have said some of this equipment had been placed there in the past, Wu said.

China claims most of the South China Sea, through which more than $5 trillion in global trade passes every year. Vietnam, Malaysia, Brunei, the Philippines and Taiwan have rival claims.

This week, coinciding with a visit to Washington by Chinese Foreign Minister Wang Yi, Admiral Harry Harris, head of the U.S. Navy's Pacific Command, said the U.S. would step up freedom-of-navigation operations in the South China Sea and that China was trying to militarily dominate East Asia.

Wu said the U.S. was employing double standards, asking why U.S. patrols in the South China Sea should not also be considered militarization.

There has been speculation that China might declare an Air Defence Identification Zone (ADIZ) in the South China Sea, similar to one it declared over the East China Sea in late 2013, to anger from Japan and the United States.

Asked if this was the case, Wu repeated the ministry's previous line that it had every right to do so, but the move would depend on the level of aerial threat China faced.

"There are all sorts of factors that need consideration," Wu said, without elaborating.

In Hanoi, a Vietnamese official said the militarization of the South China Sea was a very serious issue.

"Irrespective of the opposition and concern voiced by Vietnam and the international community, China continues to take actions that not only violate Vietnam's sovereignty, accelerate militarization of the East Sea, but also threaten peace and stability," foreign media spokesman Le Hai Binh told a briefing, employing the name Vietnam uses for the South China Sea.

Annual trade between the communist neighbors exceeds $60 billion, but anti-China sentiment is strong in Vietnam, where people are embittered over what many see as a history of Chinese bullying and territorial infringements in the South China Sea.

(Additional reporting by Martin Petty in HANOI; Editing by Clarence Fernandez)