Experts suggest Beijing is making a push for resources Hanoi cancelled exploration for in recent years.
They had pledged to accompany exiled opposition leader Sam Rainsy on his promised return to Cambodia to remove Hun Sen from power.
Rights groups say the move is not enough to stop rampant human rights violations in Rakhine state or elsewhere.
She says the US risks losing its moral authority if it does not confront China on its treatment of Uyghurs.
