Port-au-Prince, Haiti (CNN) -- The United States and Canada stepped up efforts to open other aid routes Wednesday after a leading relief agency complained that air traffic congestion in Port-au-Prince was costing lives on the ground.
Doctors Without Borders has blamed five deaths on the delays, telling reporters that flights carrying drugs, surgical supplies and dialysis machines have been diverted from Port-au-Prince to the neighboring Dominican Republic three times since Sunday.
"If we don't move now, we will lose patients, as we did," Loris de Filippi, an official at the group's hospital in the Port-au-Prince slum of Cite Soleil, told CNN Tuesday. "We lost two patients tonight because we don't have the capacity to do more."
At least 72,000 people have been confirmed dead in the magnitude 7.0 earthquake that struck Haiti January 12, according to the country's prime minister. International aid contributions have totaled hundreds of millions of dollars since then, but relief agencies on the ground say transportation bottlenecks and poor communications have slowed the delivery of food, water and medicine to survivors.
The U.S. military, which has been assisting Haitian authorities in controlling air traffic into Port-au-Prince, says the single-runway airport has been handling up to 180 flights a day. But in an effort to open up the flow, the U.S. military said Wednesday that it has obtained landing rights at the Dominican Republic's air base at San Isidro, near the capital of Santo Domingo, about 220 km (150 miles) east of Port-au-Prince.
Lt. Gen. P.K. Keen, the head of the U.S. military task force in Haiti, told CNN's "American Morning" that any aircraft identified as carrying medical supplies has priority for landing rights. Aircraft are only turned away "if there's no parking space on the ramp, and they don't have sufficient fuel to hold in their holding pattern."
But he said Wednesday night one aircraft was sent back to the Dominican Republic "that we should have put on the ground, but we did not know what was on it because it was not posted."
"If the air traffic controller knows what's on the plane and what the tail number is and he has three planes stacked up and he knows one of them has got medical supplies on it and that's the top priority identified by the government of Haiti, then that plane is going to come in," Keen said.
In addition, the Pentagon is dispatching a ship equipped with cranes that could get the port of Port-au-Prince back into operation "within a week or two, perhaps," Defense Secretary Robert Gates told reporters Wednesday during a visit to India.
And Canadian troops are working to open up an airfield in the southern city of Jacmel by Thursday, Canadian Defense Minster Peter Mackay said.
"This achievement is crucial, as it will allow the Canadian forces access to a viable landing strip 24 hours a day, making it easier to ensure a continuous flow of aid supplies and equipment," Mackay announced in a statement from Ottawa. Meanwhile, he said, two warships are landing supplies by sea, and Canada has reached an agreement with Jamaica to fly supplies into southern Haiti from there.
A senior U.S. military official, speaking on condition of anonymity, said Wednesday that the priorities for aid flights are set "by the government of Haiti first and then by the U.N. second." But the number of flights that can land at Port-au-Prince is "a sheer issue of physics and geometry; you just can't get them all in there."
"There are great people on the ground, working very, very hard to try and get as much in as they can as fast as they can, and try and keep everybody impressed that we are there to support them. But there are some people that are just not going to be happy because we can't get it all," the official said.
The U.S. military has the capability to build dirt runways that rugged cargo planes like the C-130 Hercules can use, but the equipment needed to build those is "always at a premium," the official said. The U.S. military has nearly 50 helicopters in the field that can help move supplies around the stricken country, he said.