The U.N. Refugee agency and NATO are extending and expanding their two-week-old airlift of emergency relief supplies to earthquake struck Pakistan. The UNHCR tells VOA it is crucial to get life-saving tents, blankets and stoves to survivors before winter strikes.

This is a huge operation. Over the past two weeks, the UNHCR and NATO have flown more than 800 tons of relief supplies on 50 cargo planes. But, the needs are so immense in northern Pakistan, the agency says it will be diverting aid intended for other operations.

UNHCR spokesman, Rupert Colville, says his agency will be taking supplies stocked in warehouses around the world and sending them to Pakistan, leaving the cupboard bare for other emergencies.

"We will be left with very little if there is another emergency and we have appealed to the donors and trying to make this clear to the donor countries because we have received very little money for this massive earthquake relief effort," said Rupert Colville. "We have only received just under $6 million at the moment. It is imperative we replenish these supplies. It is going to be hard with things like tents because they take a long time, a long time between ordering and actually receiving them. But, yes, if there is another big emergency somewhere in the world in the next few months, we will be in big trouble."

Mr. Colville says the UNHCR is running a $30 million shortfall. Other UN agencies also are running into financial difficulties. The United Nations reports it has received only one quarter of the $550 million appeal it launched last month.

Mr. Colville says the international response to Pakistan's devastating earthquake pales in comparison to the generous outpouring of money given by donors to last year's tsunami.

"It is a far more difficult area than the tsunami-affected areas," he said. "Sri Lanka, India, Indonesia-these are flat coastal areas, relatively easy to get to. Here you are talking the biggest mountains in the world, extremely hard to get to and viciously cold winter happening in a matter of weeks if not days. So, a lot of these affected villages will be cut off very soon by any kind of land approach and there will only be helicopters."

The United Nations estimates three million people have been affected by the earthquake, about half that number are believed to be homeless.

The UNHCR hopes to deliver over 20,000 tents, more than one half million blankets, thousands of mattresses, stoves and other supplies.