Responding to criticisms that it has turned away civilian aircraft carrying vital relief material for Haiti’s earthquake stricken capital of Port-au-Prince, the US military which is currently running the crippled airport, said the one-runway airport is simply overwhelmed.

Lack of ramp space is the key problem accounting for the bottleneck according to military officials. The facility can hold about one wide-body and five narrowbody aircraft, as well as three smaller aircraft at any given time.

“It literally became, if there was a parking space open, we would get them on the ground and get them in here. Unfortunately sometimes, you got big aircraft that occupy a big spot on the ramp and we can’t get them out fast enough — and so people are having to hold to get in,” Air Force Col. Ben McMullen told Fox News.

The airport has room for about a half-dozen planes to park, depending on their size, said Col. Buck Elton, the US Southern Command commander for south Haiti. He said the 3,000 metre strip is accustomed to hosting three aircraft on a daily basis. Approximately 40 per cent of the aircraft landing are military and 60 per cent civilian.