US Secretary of State Antony Blinken says the United States will advance a free and open Indo-Pacific and deepen treaty alliances and defence and intelligence capabilities with partners in the region.
During a visit to Indonesia, Blinken said everyone had a stake in keeping the world's most dynamic region free from coercion and intimidation and, in a veiled reference to China, said the United States and some South China Sea claimants would push back against any unlawful action.
Blinken is making his first visit to Southeast Asia since President Joe Biden took office in January, a trip aimed at shoring up relations after a period of uncertainty under the administration of Donald Trump and amid growing Chinese influence.
"We'll work with our allies and partners to defend the rules-based order that we've built together over decades to ensure the region remains open and accessible," he said in a speech at a university.
"Let me be clear: the goal of defending the rules-based order is not to keep any country down. Rather, it's to protect the right of all countries to choose their own path, free from coercion and intimidation."
Blinken, who will also visit Malaysia and Thailand this week, said the United States would strengthen defence and intelligence capabilities in the region with its allies and would defend open and secure internet.
He said China's "aggressive actions" in the South China Sea threatened more than $US3 trillion ($NZ4.4 trillion) in annual trade and countries across the region were concerned and wanted that behaviour to change.
He stressed, however, that it was not about a contest between a US-centric or China-centric region.
China claims almost the entire South China Sea as its own, despite over-lapping claims to parts of it by other coastal states and an international tribunal that ruled that China's vast claim had no legal basis.
China has rejected the US stance as interference from an outside power that could threaten Asia's stability.
Blinken said the United States was committed to a new regional economic framework, which would include more foreign direct investment and US companies identifying opportunities.
"At President Biden's direction, we are developing a comprehensive Indo-Pacific economic framework to pursue our shared objectives, including around trade and the digital economy," he said.
The United States and allies would press Myanmar's junta to end violence, free detainees and return to democracy, he added.
- Reuters