The U.S. military launched another helicopter rescue mission outside the Kabul airport last night to rescue 'less than' 20 Americans, Pentagon spokesman John Kirby revealed Wednesday. 

This is the third time American forces have launched helicopters to rescue Americans outside the airport. 

"Last night, during the period of darkness, there was an operation to be able to go out and safely evacuate evacuees back into Kabul," U.S. Army Maj. Gen. William Taylor told reporters during a briefing. "They are at Hamid Karzai International Airport and they are preparing to be evacuated." 

In this image provided by the U.S. Marine Corps, evacuees wait to board a Boeing C-17 Globemaster III, at Hamid Karzai International Airport, Kabul, Afghanistan, on Monday. (AP/Sgt. Isaiah Campbell/U.S. Marine Corps)

In this image provided by the U.S. Marine Corps, evacuees wait to board a Boeing C-17 Globemaster III, at Hamid Karzai International Airport, Kabul, Afghanistan, on Monday. (AP/Sgt. Isaiah Campbell/U.S. Marine Corps)

FORMER MARINE, CIA OFFICER HELPING AMERICAN TROOPS AT KABUL’S AIRPORT IDENTIFY EVACUEES FROM CROWDS 

Both Taylor and Kirby did not elaborate on the specifics of the mission, but said it happened within the Afghan capital. 

Kirby also said over 4,400 Americans have now been evacuated from Kabul. 

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But about 10,000 remain within its airport waiting to leave. 

U.S. officials also told Fox News earlier Wednesday that more than 400 American troops have already departed Kabul ahead of the Biden administration’s Aug. 31 deadline for all U.S. forces to leave Afghanistan.