However, it underlined that the "rebalance" to the Asia and Pacific was not aimed at China but for its own economic growth.
Referring to China's ongoing territorial dispute with countries like Brunei, Taiwan, Malaysia, the Philippines and Vietnam over the South China Sea, a top Pentagon official said it was provocative.
"And it causes tensions to be raised in the South China Sea with all the other countries in the region. I am concerned about it. I think it is an issue of concern for all of us," Commander of the US Pacific Fleet, Admiral Harry Harris, told a group of journalists here.
"It is dramatic. It is dramatic land reclamation. It is changing facts on the ground," he said.
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Harris' visit to India comes just weeks after President Barack Obama said the US was "primed to unlock" the potential of relations with India as part of its rebalance to Asia and the Pacific.
He said that as part of the US rebalance, the Pacific fleet was going to get bigger.
He said the US' submarine forces in the Pacific are at 60 per cent and surface vessel or ships at about 55 per cent.
"We will get extra ships. We are sending two extra ships to Japan. We are getting four submarines into Guam. We are going to bring an aircraft carrier around. US navy presence is going to increase over the course of this decade," he said.
"It is not about China. It is really about us. It is about recognising that our economic future lies in the Pacific and the Indian Ocean," he said.
But even as he expressed concern about China's tactics in the South China Sea, he was quick to describe the presence of Chinese submarines in the Indian Ocean as "positive" since they are engaged in anti-piracy operations.
India has voiced concern over growing Chinese military presence in Indian Ocean.