Former US president George W. Bush said he has been watching the Taliban's lightning takeover of Kabul "with deep sadness" and has urged Washington to speed up evacuations from Afghanistan.
Bush ordered the 2001 invasion to oust the Taliban regime that sheltered Al-Qaeda leader Osama bin Laden following the group's September 11, 2001 attacks on the United States that killed 2,977 people.
The 43rd US leader said in a letter released late Monday that he and former first lady Laura Bush "stand ready as Americans to lend our support and assistance," after the Taliban overran Kabul, declaring they were back in power.
Tens of thousands of people have tried to flee the hardline Islamist rule expected under the Taliban, many fearing retribution for siding with the US-backed government that ruled for the past two decades.
Evacuation flights from Afghanistan descended into chaos during the takeover as large crowds mobbed Kabul airport's runways, some clinging to a US military aircraft as it taxied for take-off.
"Laura and I have been watching the tragic events unfolding in Afghanistan with deep sadness," Bush said.
"Our hearts are heavy for both the Afghan people who have suffered so much and for the Americans and NATO allies who have sacrificed so much."
Bush voiced confidence that the evacuation would be effective but urged President Joe Biden to cut red tape and speed up the removal of Afghans and Americans threatened by the Taliban.
"We have the responsibility and the resources to secure safe passage for them now, without bureaucratic delay," he said.
The Bush administration was berated for turning its focus away from Afghanistan in the early years of the conflict to invade Iraq, allowing the fight with the Taliban to drag on with no clear purpose.
But the former president argued that the Afghan conflict had not been in vain, saying US troops had taken out "a brutal enemy" while building schools and providing medical care.
He said the armed forces had "kept America safe from further terror attacks, provided two decades of security and opportunity for millions and made America proud."