Monsoon rains soaked much of Central Asia more than a month ago, triggering massive floods in Pakistan. At one point around 20 percent of the country was under water.
Pascal Cuttat, the Islamabad director of the ICRC, said that while flood waters were receding in parts of northern Pakistan, residents in the south were still on the run.
Food and shelter for Pakistanis affected by the flood are critically needed, the ICRC said, but the impacts from water-borne illnesses are long-term concerns.
"We are still very worried about the health situation," said Cuttat in a statement. "It stems directly from the fact that millions of the displaced lack access to clean water and thus from the potential spread of water-borne diseases, such as diarrhea, and vector-borne diseases, such as malaria."
The Pakistani response to the flooding is impacted by the looming threat from insurgents operating in the provinces bordering Afghanistan. Cuttat said using the relief effort as a political tool was detrimental to the well-being of the Pakistani public.
"Any attempt to deny access to the victims, whether by threatening to attack aid workers or by other means, would only hinder a massive humanitarian response to one of the biggest natural disasters in the history of Pakistan," he said.