"The world is not doing enough," Egeland said on Thursday.
He said he was appealing to Nato and other potential donors to step in with "a second Berlin air bridge" of helicopters flying in relief supplies and evacuating perhaps hundreds of thousands of people from the damaged areas of Pakistan and India.
Egeland noted that the two countries had agreed to step up cross-border relief, but said old tensions between the neighbours were holding up implementation of relief cooperation.
Pakistani officials were questioning whether the Indian military could be involved and had been insisting that any Indian helicopters used in the Pakistani-administered Kashmir side of the border be flown by Pakistani pilots, he said.
Egeland said he was pleased with the Nato response so far, but that he had been telling alliance officials they need to do more, "think bold, think big", in building up its involvement.
Nato Secretary-General Jaap de Hoop Scheffer, speaking during a visit to the Ukrainian capital, Kiev, said the alliance will have a meeting in Brussels on Friday to discuss earthquake aid and that it was possible Egeland would attend to present his request in person.
"It will certainly be on the agenda," De Hoop Scheffer said.
"Nato fully realises the gravity of the situation. Nato will, within Nato's means and capabilities, act accordingly." De Hoop Scheffer said the alliance had already flown in "many, many tons of goods" from Germany and Turkey.
"Nato fully realises the gravity of the situation. Nato will, within Nato's means and capabilities, act accordingly"
Jaap de Hoop Scheffer,
Military planners at Nato's headquarters in Belgium were holding talks on Thursday to generate more forces for the relief effort.
Nato officials said they had received offers, but declined to go into details ahead of Friday's meeting.
The alliance is expected on Friday to approve the dispatch of medics and hundreds of military engineers to clear roads and help reconstruction.
However, allied commanders are struggling to muster the helicopters needed to carry aid into remote mountain areas.
Nato has said it lacks the light helicopters that are needed in Pakistan at the moment, but the alliance on Wednesday started its biggest ever joint airlift with the UN High Commissioner for Refugees (UNHCR) to get supplies into Pakistan, a spokesman said.
Egeland said only $86 million had been pledged so far to the United Nations' appeal for $312 million in donations for the earthquake victims.