NEW DELHI: Naval chiefs of Quadrilateral nations - India, US, Australia Japan - on Thursday called China "a disruptive power" as they pushed for a new regional security architecture to face up to Beijing's aggressive designs."China is a disruptive, transitional force in the Indo-Pacific," US Pacific Commander Admiral Harry Harris said on the concluding day of Raisina Dialogue as he shared the dais with Indian navy chief Admiral Sunil Lanba , Australian navy Chief Vice Admiral Tim Barret and Admiral Katsutoshi Kawano, chief of staff, joint staff, Japan. For the first time, diplomatic representative from Indonesia was also present to dispel any impression that the ' Quad ' was ganging up against China."We must be willing to take tough decisions in 2018 against unilateral ways to change the use of global commons with rule-based freedom of navigation," Harris said, his views finding echo in his counterparts from the other three countries of the 4-nation grouping.Admiral Sunil Lanba said China's navy had made big changes to its deployment patterns in waters around India. "They have a base in Djibouti. They have developed a port in Hambantota (Sri Lanka) though we have been told there will be no (permanent) presence (of the Chinese navy) there," he said. China, he said, is "developing ports and infrastructure that are not viable". Japan's Admiral Katsutoshi Kawano was more forthright. "China's military power is becoming more powerful and is expanding. In the East and South China Seas, China has been ignoring international law. In order to deter Chinese provocations, India, the US, Australia and Japan have to cooperate with one another," he said.Foreign secretary S Jaishankar though said China has been a "motivator and example" for India in some ways. "People think if China can do that why can't we. To some extent, China has opened up the international order allowing India to make its presence felt. Its rise has many facets to it," Jaishankar told the gathering, adding India would have to step up and play a better game."What we are seeing right now is not just the rise of a global power but a very different power. Also, whether that power would be a model to others is an open question," he said. In the current global system of uncertainty, India, he said, is part of the "solution". He said India had "committed around $25-30 billion in credits and grants in our extended neighbourhood, from East Africa to South East Asia".