Updated

International lenders are estimating that this summer's floods caused $9.5 billion in damage to Pakistan's infrastructure, agriculture and other sectors, a government official said Wednesday.

The estimate, drafted by the Asian Development Bank and the World Bank in consultation with Pakistani leaders, underscores the financial challenges facing Pakistan, a U.S.-allied nation that is battling an Islamist insurgency and was relying on international loans before the deluge.

Although other nations, including the U.S., have contributed millions to the relief effort, they have warned Pakistan that they cannot foot the entire recovery and reconstruction bill, which some have estimated could surpass $40 billion. U.S. officials, in particular, have urged Pakistan to improve its anemic tax collection to aid its long-term rebuilding.

The $9.5 billion figure refers only to existing values of roads, buildings, irrigation systems and other devastated sectors that were evaluated nationwide, not what it will cost to replace them, said the government official familiar with the report.

The replacement costs will depend on which projects the government chooses to pursue and whether it wants to rebuild certain structures in the same fashion or better, he said. The official requested anonymity because the draft findings have yet to be officially released.

The floods began in late July during unusually heavy monsoon rains, eventually covering one-fifth of the country and affecting some 20 million of its 175 million people. Nearly 2,000 people died, while millions were left homeless, according to the United Nations.

Dozens of bridges were washed away, while more than 1.9 million homes were damaged or destroyed. Around 5.9 million acres (2.4 million hectares) of farmland were damaged, a severe blow to agriculture, the most important pillar of Pakistan's economy. Even as nearly all of the people displaced in the northwest have returned to their homes — or what's left of them — parts of southern Sindh province are still under water.

Aid groups have struggled all along to raise funds to help Pakistan. With the disaster unfolding relatively slowly, and the number killed low compared to other major disasters such as the Haiti earthquake, experts said many countries and donors did not immediately realize the magnitude of the disaster. But there also are concerns that corruption and inefficiency in Pakistan's government may lead to squandered aid.

The U.N. has appealed for just over $2 billion to help Pakistan's emergency relief and early recovery, but has received only about one-third of that.

Spokesmen for the Asian Development Bank and the World Bank declined to comment on the $9.5 billion figure, saying it was premature to discuss it before the preliminary report is released at a meeting of countries in the Friends of Democratic Pakistan group in Brussels on Thursday.

The Pakistani government has come under fire for its patchy response to the floods, and many have questioned its ability to carry out a recovery plan, especially if it fails to institute major economic reforms. Before the floods, Pakistan's economy was kept afloat by billions of dollars in loans from the International Monetary Fund.

Daniel Feldman, a U.S. State Department deputy special representative for Pakistan and Afghanistan, said much of the money to recover from the floods will have to come from Pakistan. To raise it, Pakistan "will need to engage in some fundamental reforms and, in particular, tax reform," he told reporters in Washington on Tuesday.

On Wednesday, Pakistani Prime Minister Yousuf Raza Gilani promised that the government would share its "national strategy for rehabilitation and reconstruction" at a meeting of the Pakistan Development Forum set for November.