NEW DELHI (Reuters) - The head of the U.S. military’s Pacific command called China a disruptive power in the Indo-Pacific region on Thursday and urged countries in the area to build capabilities and work together to ensure free and open seas.

FILE PHOTO: U.S. Navy Admiral Harry Harris Jr, head of the Pacific Command, attends at a Fullerton Lecture on "Challenges, Opportunities and Innovation in the Indo-Asia-Pacific", in Singapore October 17, 2017. REUTERS/Edgar Su

Admiral Harry Harris, known for his combative views on Beijing’s South China Sea expansion, was speaking at a security conference sponsored by the Indian government, where he was joined by the chief of staff, joint staff of Japan and the head of the Indian navy.

The three countries - the United States, Japan and India - have grown increasingly concerned about China’s assertive military posture in the region and sought to draw closer, with Australia, in a “quad” of liberal democracies.

“I believe the reality is that China is a disruptive transitional force in the Indo-Pacific, they are owner of the ‘trust deficit’ that we all have spent the last hour talking about,” Harris said referring to the discussions of the panel.

The United States has criticized China’s construction of islands and build-up of military facilities in the South China Sea, saying they could be used to restrict free nautical movement.

China says there is no issue with freedom of navigation in the South China Sea and opposes efforts to use it as an “excuse” to infringe on China’s sovereignty and security interests.

Harris said China’s actions had cause disquiet in countries stretching from the Philippines to Malaysia and Vietnam. He said it was time countries took firmer measures to ensure maritime stability.

“We must be willing to take the tough decisions to ensure the Indo-Pacific region and the Indian Ocean remain free, open and prosperous,” he said. “This requires like-minded nations to develop capacities, leverage each other’s capabilities.”

Harris had earlier proposed joint patrols with the Indian navy in the Indian Ocean. New Delhi, worried about a backlash from China, said no such actions were planned.

But India has begun holding trilateral naval exercises with the U.S. and Japan that military experts say could eventually include Australia as well.