The remarks from Michael Collins, Deputy Assistant Director at the Central Intelligence Agency's East Asian Mission Centre, came as the Pentagon yesterday said that a US Navy surveillance aircraft was intercepted on Sunday by two Chinese J-10 fighters in an "unsafe" manner over the disputed East China Sea.
China and Japan, a longtime US ally, have rival claims over a chain of islands in the East China Sea. Tensions have flashed several times over the Senkaku Islands, which Beijing claims as Diaoyu Islands.
China has also been locked in territorial disputes with several of its other neighbours in the South China Sea, parts of which is claimed by Taiwan, Malaysia, Brunei, Vietnam and the Philippines.
It has heavily militarised some islands with major land reclamation work, drawing protests from several countries including the US - which has carried out "freedom of navigation" operations through the waters claimed by China.
At the Aspen Institutes' 2017 Security Forum, Mr Collins said: "They (Chinese) are increasingly resorting to coercive, assertive practices to achieve their ends, things that we don't subscribe to...And for that reason, for us to understand issues such as North Korea, South China Sea, trade, how China is approaching these issues, we have to be mindful of that."
He, however, said that the Chinese behaviour "does not mean" the US and China were headed for war in the region. "They do not want backlash in East Asia. And they need a stable, robust relationship with the US and the international community for the economic needs and the technology they need to move their country forward," Mr Collins said.
"We have to be mindful about what they face internally...And to them, they have to keep that quite secure. To that end, they need stability and close relations and stay in relations with United States," the CIA official said.
While Mr Collins did not refer to the ongoing India-China border standoff in the Sikkim sector, Japanese Ambassador to the US Kenichiro Sasae brought India into the picture. "We continue to develop some of the alliance network and network of friends, including ASEAN, and also India these days," he said.
"The Chinese ambition is not simply limited to try to equal with United States in the area of Asia-Pacific... That is not simply for the economic ambition, it's more of the strategic ambition. They want to compete with US," he said.
He said China has global expansion goals.
"It is obvious. I think that dream is like 12 and 13 century of Ming Dynasty. They reached over to the Indian Ocean and into the Middle East. I think that's the region they might have are deep into their mind," he said, responding to a question on China's One Belt One Road (OBOR) initiative.
The OBOR is an ambitious Chinese plan to link the country to Africa and Europe through several trade corridors.
According to Bonnie Glaser, senior adviser for Asia and the director of China Power Project, Centre for Strategic and International Studies, the Chinese are trying to organise the regions in a way that it is more Sino-centric, where China can prevail and can essentially compel other nations in the region to put China's interest first and show deference to China.
"That is a major challenge for the US," he said.
"We have to think about China not just in terms of discrete issues like North Korea or cyber as we have talked about at this conference, but more of a global challenge, and we need more of a whole of government strategy to deal with the growing strategic competition between the US and China.
The competition is inevitable; war is not," Glaser said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)