US Secretary of State Antony Blinken on Wednesday cut short a trip to Southeast Asia after a member of his delegation contracted the coronavirus, a spokesman for the US State Department said.

The top US diplomat was due to meet Thai officials in Bangkok on Thursday after visiting Indonesia and Malaysia, but this final leg of the three-country tour has been cancelled.

Blinken told Thai foreign minister Don Pramudwina that he "would be returning to Washington DC, out of the abundance of caution," the spokesman said.

A journalist with the travelling party tested positive for Covid on arrival in Malaysia on Tuesday night, he added.

No other members of the press or advisers close to Blinken returned a positive result, he said.

The US embassy in Malaysia said in a statement that the person with Covid-19 did not participate in any of Blinken's planned activities in Kuala Lumpur.

The journalist is now in isolation in Kuala Lumpur, in line with local regulations.

The state department's spokesman told reporters travelling with Blinken that the decision to end the tour was taken to "mitigate the risk of the spread of Covid-19 and to prioritise the health and safety of the US travelling party and those they would otherwise be in contact with".

The US embassy in Jakarta said on Twitter that all members of the group had tested negative in Indonesia.

Blinken's plane will make a short technical stopover in Thailand, with no official talks on the agenda, before he returns to the United States.

He was originally scheduled to make a stop in Hawaii on the way back to Washington.

Blinken's tour was aimed at challenging a more assertive China and re-establishing US influence in Asia after the turbulence and unpredictability of the Donald Trump era. 

He began the trip in Jakarta where he met with Indonesian President Joko Widodo, before giving a joint news conference on Wednesday with Malaysian Foreign Minister Saifuddin Abdullah in Kuala Lumpur.

Before arriving in Indonesia, Blinken participated in a G7 foreign ministers' meeting in Britain.