"I am particularly proud to welcome Comoros as the newest member of the WTO," said the organisation's director-general Ngozi Okonjo-Iweala.

"Comoros's membership will add a valuable voice to the multilateral trading system as it has shown commitment to the values of the WTO and has clearly demonstrated willingness to adapt to its rules and principles."

The archipelago of three islands and about 850,000 people joins 35 other members in the least-developed countries category.

WTO members approved the accession of the Comoros during the trade body's 13th ministerial conference in Abu Dhabi in February.

Accession can take years as it entails long negotiations with all WTO members, which each have the power to block a country from joining.

The last two countries to join the WTO were Afghanistan and Liberia in 2016. Kazakhstan and the Seychelles joined in 2015.

Twenty-three countries have accessions in progress. East Timor's membership is due to become effective on August 30, after their application was also approved at the  February meeting.

Comoros President Azali Assoumani, a former military ruler who came to power in a 1999 coup, said in Abu Dhabi that joining the WTO would be "immensely beneficial for our entire economy, for public and private enterprises, and for consumers.

"It will contribute to our country's trade diversification and partnership efforts, to its integration into regional, continental and global value chains."

In joining the Geneva-based WTO, the Comoros also announced its formal acceptance of the WTO Agreement on Fisheries Subsidies.

The 2022 deal bans subsidies that contribute to fishing that is illegal, unreported or unregulated.

It also bans subsidies for fishing of overstretched stocks and in unregulated high seas, with additional flexibility baked in for developing nations.

Fifty-six members have now accepted the agreement, including the European Union, the United States, China and Russia.

For the agreement to enter into force, two-thirds of WTO members -- now 110 members -- must formally accept the protocol.