Taliban authorities kicked off celebrations of the third anniversary of their rule over Afghanistan on Wednesday at the former US Bagram air base.

Hundreds of people, including Chinese and Iranian diplomats, gathered at the base, around 40 kilometres (25 miles) outside Kabul, for speeches and a military parade.

The Taliban government has "the responsibility to maintain Islamic rule, protect property, people's lives and the respect of our nation", Prime Minister Mohammad Hassan Akhund, who was not present, said in a statement read by his chief of staff.

Helicopters had carried senior Taliban officials to the event at Afghanistan's biggest air base, which served as the linchpin of US-led operations in the country for two decades.

Taliban forces seized the capital Kabul on August 15, 2021, after the US-backed government collapsed and its leaders fled into exile. The anniversary is marked a day earlier on the Afghan calendar.

"On this date, Allah granted the Mujahid nation of Afghanistan a decisive victory over an international arrogant and occupying force," Akhund said in a statement on Tuesday.

Extra security was deployed in the capital and the Taliban's spiritual home of Kandahar ahead of the "day of victory", with Islamic State group attacks a continued threat in the country.

In the three years since they ended their 20-year insurgency, the Taliban government has consolidated its grip on the country, implementing laws based on its strict interpretation of Islam.

The government remains unrecognised by any other state, with restrictions on women, who bear the brunt of policies the United Nations has called "gender apartheid", remaining a key sticking point.

- Banners, flags and poetry -

The days before the celebrations, workers were busy putting up banners and billboards reading "Congratulations" with the anniversary date around Kabul.

Vendors selling flags of the Islamic Emirate of Afghanistan -- the Taliban government's formal name for the country -- dotted the city, the white and black standard also fluttering over streets.

Celebrations featuring athletes and poetry readings were due to be held at a stadium in the capital.

Heavy security and decorations also went up in the southern city of Kandahar -- the birthplace of the Taliban movement and home to the reclusive leader Hibatullah Akhundzada, who rules through religious edict.

Security has been a key priority for Taliban authorities, and while many Afghans express relief at the end of 40 years of successive conflicts, the economy remains in crisis and the population mired in a worsening humanitarian crisis.

A joint statement from international non-governmental groups warned of the growing aid funding gap, with 23.7 million people in need of humanitarian assistance.

Human Rights Watch (HRW) reiterated calls for pressure on the Taliban government to lift restrictions on women, who have been squeezed from public life and banned from secondary and higher education.

"The third anniversary of the Taliban's takeover is a grim reminder of Afghanistan's human rights crisis, but it should also be a call for action," said Fereshta Abbasi, Afghanistan researcher for HRW.