TOKYO: Pentagon chief Lloyd Austin arrived in Japan on Monday, as he and top US diplomat Antony Blinken began their first overseas trip, looking to rally key Asian allies as a bulwark to China.

The pair, who travelled separately, will meet in Japan for the first leg of their trip, holding talks with their counterparts as well as Prime Minister Yoshihide Suga.

They will both continue on to South Korea, before Defence Secretary Austin heads separately to India and Secretary of State Blinken holds talks back in the United States with Chinese officials.

President Joe Biden's team has been deliberately slow to start the usually hectic pace of diplomatic travel that marks a new administration, hoping to set an example discouraging travel during the pandemic.

But the administration has also made clear it wants to reset US relations with the rest of the world, particularly traditional allies, after the tumult of the Donald Trump era.

In a joint opinion piece in the Washington Post on Monday, Austin and Blinken said they would look to "revitalise our ties with friends and partners".

The visit will also be about presenting a united front on the challenges posed by China.

"Our combined power makes us stronger when we must push back against China's aggression and threats," they wrote.

"Together, we will hold China accountable when it abuses human rights in Xinjiang and Tibet, systematically erodes autonomy in Hong Kong, undercuts democracy in Taiwan or asserts maritime claims in the South China Sea that violate international law.

"If we don't act decisively and lead, Beijing will."