Rubio called China the "most potent, dangerous adversary" during his confirmation and is expected to work with India, Japan, and Australia to counter this.

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.

By Daphne Psaledakis, Simon Lewis and Trevor Hunnicutt WASHINGTON (Reuters) -U.S. Secretary of State Marco Rubio met with counterparts from Australia, India and Japan on Tuesday, a meeting he said will stress the importance of working with allies "on the things that are important to America and Americans.