US Secretary of State Marco Rubio will meet Chinese Foreign Minister Wang Yi on Wednesday on the sidelines of a regional gathering led by the Southeast Asian bloc ASEAN, where the two top diplomats are expected to discuss a possible September summit between their leaders.Rubio's meeting with Wang, which was confirmed by a State Department official, comes amid a fragile truce between the global superpowers that could be complicated by US President Donald Trump's accusations last week of Chinese meddling in US elections, which Beijing has denied.

The wider meeting in Manila takes place amid renewed hostilities and a potential new front in the conflict between the US and Iran, and as diplomatic tension flares between Beijing and close US ally the Philippines over an incident in the South China Sea that led to the summoning of ambassadors in both capitals.

Rubio joined a meeting early on Wednesday with the foreign ministers of the Association of Southeast Asian Nations, where he is expected to stress Washington's commitment to stand up for maritime rights in the South China Sea and honor US obligations to regional allies.

In an opinion piece in Philippine media published on his arrival in Manila on Tuesday that took aim at Beijing, Rubio said Southeast Asian countries are confronting "new and coercive threats" and the US was committed to upholding freedom of navigation.