MOSCOW (Reuters) - Russia has invited Afghanistan's Taliban to its biggest annual economic forum as Moscow moves to remove a ban on the Islamist movement, a senior Russian diplomat was quoted as saying on Monday.

Since the Taliban seized power in August 2021 as U.S.-led forces withdrew after 20 years of war, Russia has been slowly building ties with the Taliban, though the movement is still officially outlawed in Russia.

Russia's foreign and justice ministries have reported to President Vladimir Putin on the issue of removing the ban, Zamir Kabulov, director of the Second Asia Department at the Russian Foreign Ministry, told state news agency TASS.

Some questions remain, Kabulov was quoted as saying, though he said that an invitation to attend the June 5-8 St Petersburg international economic forum had been extended to the Taliban.

Afghan leaders, he said, were traditionally interested in the purchase of oil products.

The St Petersburg forum, which once hosted Western CEOs and investment bankers from London and New York, has changed significantly amid the Ukraine war which has triggered the biggest crisis in Russia's relations with the West since the 1962 Cuban Missile Crisis.

Western investors seeking a slice of Russia's vast resource wealth have now been replaced by businesses from China, India, Africa and the Middle East.

The Taliban, which means "students" in the Pashto language, emerged in 1994 around the southern Afghan city of Kandahar. It was one of the factions fighting a civil war for control of the country following the withdrawal of the Soviet Union and subsequent collapse of the government.

It originally drew members from so-called "mujahideen" fighters who, with support from the United States, repelled Soviet forces in the 1980s.

In 2003, Russia formally labelled the Taliban a terrorist organisation, though it had periodic informal contacts with the movement.

(Reporting by Lucy Papachristou and Guy Faulconbridge; Editing by Andrew Cawthorne)