Biden vows to 'hunt down terrorists' one year on from Kabul airport blast that killed hundreds

US President Joe Biden vowed to "hunt down terrorists wherever they may be" as he marked one year since an explosion at Kabul airport killed 13 American troops and hundreds of Afghan civilians. 

The 27 August explosion at the airport - where massive crowds of Afghans had gathered to flee the newly-returned Taliban authorities - was linked to IS-K, the Afghanistan branch of the Islamic State group. 

Biden condemned the "heinous" attack in a statement published by the White House on Friday. 

"Our nation will forever mourn their sacrifice and honor the memory of those 13 precious souls, stolen from their families, loved ones, brothers- and sisters-in-arms far too soon while performing a noble mission on behalf of our nation," the president remarked. 

Just weeks after the US shot down Al-Qaeda leader Ayman al-Zawahiri on Afghan soil, the US Commander in Chief said his administration would continue to target terrorists "who seek to harm the United States" wherever they are.

Biden's administration was severely criticised for its decision to withdraw soldiers from Afghanistan. As US-led foreign troops ended their twenty-year missions in the central Asian country, the Taliban were able to launch a lightning offensive, taking control of the capital on 15 August.

The president defended the withdrawal in Friday's statement, saying: "We now maintain pressure against terrorist threats without keeping thousands of troops in harm’s way on the ground in Afghanistan."

The killing of Zawahiri in an upmarket district in Kabul has raised questions over whether the Taliban are adhering to the Doha agreement - in which it committed to preventing groups and individuals including Al-Qaeda from "using [Afghanistan’s] soil" for "recruiting, training and fundraising" - signed ahead of the US withdrawal. 

It remains unclear whether Zawahiri was conducting such activities during his time in Kabul or whether he was working directly with the Taliban. 

However, Zawahiri was allegedly at a property owned by a senior aide to Sirajuddin Haqqani, the Taliban’s acting interior minister, according to International Crisis Group. 

On Thursday, the Taliban said they have not yet found Zawahiri's body and are continuing investigations.