A US and Southeast Asian push for a freeze in "provocative" acts in disputed waters has set the stage for a showdown with China at a regional security summit, analysts said.
Recent acts by China, including the positioning of an oil rig in waters also claimed by Vietnam, have alarmed neighbours and Washington ahead of the ASEAN Regional Forum (ARF) on Sunday in Myanmar's capital Naypyidaw.
"The US is lobbying for a strong push at the ARF for adherence to international law to keep the situation in the South China Sea peaceful," said Australia-based Southeast Asia expert Carl Thayer.
"It will also support a freeze on provocative activities," he told AFP, adding however that Beijing will likely "take a hard stance on US interference".
The ARF is an annual security dialogue among foreign ministers of the 10-member Association of Southeast Asian Nations (ASEAN) and key partners, including Australia, China, India, Japan, South Korea, Russia and the European Union.
Daniel Russel, US President Barack Obama's pointman for East Asia, said that while Washington's policy is not to "confront or contain China", it will be frank during the discussions while seeking to lower tensions.
"We don't pull punches. We don't avoid difficult but important issues," he told reporters in Washington ahead of the departure of his boss, US Secretary of State John Kerry, to Myanmar for the ARF and related meetings.
The one-day ARF is also expected to touch on nuclear-armed North Korea's belligerence and territorial disputes between China and Japan in the East Sea.
Analysts said China is expected to reject calls for a freeze in activities in the South China Sea by insisting that these are not provocative.
Beijing maintains it has "indisputable sovereignty" over almost the entire sea, including waters, islands, reefs, shoals and outcrops nearer to other countries.
ASEAN states Brunei, Malaysia, the Philippines and Vietnam are claiming parts of the sea, while Taiwan is a sixth claimant.
Ties between China and Vietnam sank to their lowest point in decades after Beijing in May moved a deep-sea oil rig into disputed waters near the Paracel Islands, triggering deadly anti-China riots in Vietnam.
