US Secretary of State Marco Rubio on his first full day in office on Tuesday warned jointly with Japan, India and Australia against coercive actions in Asia, in an apparent warning to China over its actions at sea.

On his first full day as secretary of state, Marco Rubio is meeting with his counterparts from a group of countries known as the Quad: the United States plus India, Japan and Australia, representing nearly 2 billion people and more than a third of global GDP.