Philippine vessels carrying out a routine mission to the Second Thomas Shoal were "harassed (and) blocked" by Chinese maritime militia and coast guard ships on Tuesday, according to Manila.

Asked about the encounter on the final day of an Association of Southeast Asian Nations (ASEAN) summit in Melbourne, Albanese said the behaviour was dangerous and risked miscalculations that could lead to further escalation.

"I am very concerned and Australia is concerned about any unsafe and destabilising behaviour in the South China Sea," Albanese said.

(Reporting by Lewis Jackson; Editing by Alasdair Pal and Tom Hogue)