French President Emmanuel Macron and his Indonesian counterpart Joko Widodo on Saturday vowed to work toward a "true strategic partnership", France's presidency said, after Paris was locked out of a defence pact between the US, UK and Australia.

Since losing a major submarine deal with Canberra, which joined an AUKUS alliance to better counter China, France has sought solace in leading Southeast Asian nations for deeper strategic ties in the Pacific region.

On the sidelines of the G20 summit in Rome, Widodo and Macron met for half an hour discussing the growing economic clout of the region and the rivalry between the United States and China.

They "decided to work on a true strategic partnership in the Indo-Pacific," said the French side.

It would notably "cover the question of the ecological transition, of support for employment and growth in Indonesia and the post-Covid revival", the French presidency added.

The talks came ahead of a Jakarta visit by French Foreign Minister Jean-Yves Le Drian with Indonesia due to take over the rotating G20 presidency after Italy.

Macron is again expected to raise Indo-Pacific issues later Saturday during talks with Indian Prime Minister Narendra Modi.

Widodo and his French counterpart also reviewed coordination at ASEAN, Southeast Asia's regional bloc, where Indonesia, with a population of more than 270 million, plays a pivotal role.

France assumes the rotating EU presidency in 2022.