Annan said on the eve of a key donors conference that only 30 percent of the money pledged for quake relief had been donated so far. He said that paled in comparison to donations after the Dec. 26 earthquake and tsunami that devastated 11 nations on the Indian Ocean.
"I think there is no doubt that donors' response has been weak and tardy," Annan said. "When the tsunami struck at the 10-day point we had 80 percent of the money we needed. In the case of Pakistan at the 10-day point we had 12 percent. Today we have 30 percent."
Annan also warned of a "gigantic task" ahead for quake recovery efforts in northern Pakistan, where most of the deaths occurred.
The U.N. chief visited families sheltering in tents inside the quake zone and said he would renew funding appeals at Saturday's conference for what he called "one of the largest humanitarian tragedies we've had to deal with."
He said the difficulties posed by winter's onset and the logistics of reaching mountain villages made the Oct. 8 quake disaster comparable to the tsunami, which killed 180,000 people.