A photograph showing the Afghan civilians - some clutching luggage, others bottle-feeding infants - on the C-17 cargo aircraft has gone viral on social media
The C-17 Globemaster III can carry 134 passengers, including 54 on side seats and 80 on pallets on the floor
US officials have said the insurgents could make a move within days on the city, whose population of 5 million people has been swollen with thousands fleeing other parts of the country
NATO Allies are deeply concerned about the high levels of violence caused by the Taliban's offensive, including attacks on civilians, targeted killings, and reports of other serious human rights abuses
A flurry of diplomatic calls between the US and Pakistan in recent days has fuelled speculation the Pentagon is scouting for new bases to use against the Taliban.
However, Pakistan's Foreign Office has denied the rumors saying, "no such proposal is expected."