A senior US State Department official has encouraged Australia and other nations in the Asia-Pacific to build good relations with China.

Joseph Yun, the acting assistant secretary in the US State Department's Bureau of East Asian and Pacific Affairs, said in testimony to a US congressional committee in Washington DC on Tuesday that America was moving ahead with strengthening its alliances with longstanding allies such as Australia, Japan and South Korea.

The US has also increased its engagement with Indonesia, Vietnam, Singapore, Malaysia, Brunei, New Zealand and the Pacific Islands as part of its "strategic rebalance" focusing on the Asia-Pacific, rather than Europe and the Middle East.

The re-balance has been viewed as a strategy to counter China's influence in the region, but Mr Yun said the US is focused on building a stable relationship with the Asian power.

"Our efforts with China, which include an unprecedented number of high-level and people-to-people exchanges and interactions, aim to build a stable, multifaceted bilateral relationship that is grounded in reality, true to our principles and interests, and focused on results," Mr Yun told the US house committee on foreign affairs, subcommittee on Asia and the Pacific.

"We understand that countries in East Asia, South Asia and the Pacific seek good relations with China, and we encourage them to do so.

"A China that plays by established rules and norms, actively co-operates in addressing regional challenges, and is a source of global economic growth benefits all of us."

Mr Yun also pointed to the growing influence of India in the Asia-Pacific.

"India boasts a $US2 trillion ($A1.96 trillion) economy today," he said.

"Experts anticipate that India's economy will continue growing through the coming decades until India peaks demographically in 2060.

"At that time, India will represent one-fifth of the global economy."