It was only when his plane left Kabul that he realised he was going, Mr Ghani said on BBC Radio 4's Today programme.

He was heavily criticised and accused of abandoning the country at the time. He is now in the United Arab Emirates.

Mr Ghani made the comments in conversation with Gen Sir Nick Carter, the UK's former Chief of the Defence Staff, who was guest-editing the Today programme on Thursday.

As the day started, Mr Ghani recalled, Taliban fighters had agreed not to enter Kabul - "but two hours later, this was not the case".

"Two different factions of the Taliban were closing in from two different directions," Mr Ghani explained. "And the possibility of a massive conflict between them that would destroy the city of five million and bring havoc to the people was enormous."

He agreed to let a number of those close to him leave Kabul - including his wife, who he said did so very reluctantly. His national security advisor also left, and Mr Ghani waited for a car to take him to the ministry of defence.

The car never came. Instead, the national security advisor returned, along with the "terrified" chief of presidential security, and told Mr Ghani they would "all be killed" if he took a stand.

"He did not give me more than two minutes," Mr Ghani said. "My instructions had been to prepare for departure for [the city of] Khost. He told me that Khost had fallen and so had Jalalabad.

"I did not know where we will go. Only when we took off, it became clear that we were leaving [Afghanistan]. So this really was sudden."

In the wake of his departure, Mr Ghani was roundly criticised by many in Afghanistan including his vice-president Amrullah Saleh, who called it "disgraceful".