US President Joe Biden has defended his decision to withdraw US troops from Afghanistan - a move which led to Taliban militants returning to power.

Staying longer was not an option, Mr Biden said in an address to the nation, a day after the end of a 20-year US presence in Afghanistan.

He praised troops for organizing an airlift of more than 120,000 people wishing to flee the Taliban regime.

The Islamist militants have been celebrating what they call a victory.

US-led troops went into Afghanistan in 2001, ousting the Taliban in the wake of the devastating 9/11 attacks, blamed on al-Qaeda - a militant jihadist group then based in the Asian country.

Mr Biden has been widely criticised - at home and by his allies - over the abrupt manner of the US withdrawal, which led to the unexpected collapse of the Afghan security forces US troops had trained and funded for years.