Islamabad, Oct 22 (SPA) - The international response to the Pakistani earthquake has been inadequate and the speed and scale of relief for millions of survivors has to be intensified as winter approaches, the United Nations said on Saturday. Two weeks after the huge quake flattened towns and villages across the mountainous region, killing more than 50,000 people and injuring more than 74,000, countless thousands remain cut off and have not been reached by medical and other aid teams. "The immensity of the disaster is still becoming clearer daily," U.N. humanitarian coordinator for Pakistan Jan Vandermoortele told a news conference in Islamabad. "Progress is being made," he said. "However people in the valleys remain unreached, the terrain is making it a logistical nightmare to sustain the support," he said of remote, cut-off valleys. "The top priority overall is tents and emergency shelter," he said. "We need helicopters, a lot of helicopters and all types of helicopters." Vandermoortele said only about 50 helicopters in all were operational, although more were on the way, and he was hopeful for a fleet of 100. He welcomed an announcement from NATO on Friday that the alliance would send up to 1,000 troops and several more helicopters. "It will help a lot," Vandermoortele said of the extra NATO aid. "But we need more, we need much more, and we need it much faster," he was quoted as saying by Reuters. Another aid official said up to 541,000 tents were needed but with limited global supplies, a shortfall of up to 200,000 was possible. --SPA 1359 Local Time 1059 GMT www.spa.gov.sa/297874