The Western allies will work with the Federated States of Micronesia, Kiribati, and Nauru to provide better internet capacity.

A joint statement between six countries released on Sunday included Australian Foreign Minister Marise Payne, Japan Foreign Minister Yoshimasa Hayashi, and US Secretary of State Antony Blinken.

The six-country partnership would result in higher quality and more reliable and secure communications to about 100,000 people, the statement said.

"This will support increased economic growth, drive development opportunities, and help to improve living standards as the region recovers from the severe impacts of COVID-19."

The joint infrastructure investment comes at a time of "unprecedented economic and strategic challenges in our region."

Concern have increased in the Indo-Pacific region amid tensions between China and Taiwan.

Chinese fighter jets continue to fly over Taiwan, while Defence Minister Peter Dutton said it was "inconceivable" Australia would not support the United States in a war over the island.

Better access to digital technologies and improved connectivity are said to enhance economic and social benefits and improve sustainable development.

"They also help increase the availability of digital government services, particularly in education and health," the joint statement said.

"And provide businesses and households with improved access to services, information and trade, and employment opportunities."

The cable will connect Kosrae, Nauru, and Tarawa with an existing cable at Pohnpei, providing online connectivity for the first time through a submarine cable.

Australian Associated Press