The reconstruction bill after the deadly floods that hit Nepal last month will amount to $US4.78 billion ($6.67 billion), its foreign ministry says.
Spokesman Lok Bahadur Chhetri said that $US57.67 million ($80.43 million) was needed for short-term reconstruction and recovery over the next six months.
Approximately $US4.71 billion ($6.57 billion) was required for long-term reconstruction adapting to a rapidly changing mountain environment, he added.
"Given the scale and extent of the damage, the government is also undertaking a comprehensive post-disaster needs assessment to determine the full extent of loss and damage and the requirement for recovery, rebuilding and reconstruction," Mr Chhetri told reporters on Friday.
At least 12 hydropower projects have been engulfed in mud and debris, and whole villages wiped off the map, after a glacier collapse near the Nepal-Tibet border caused a tsunami-like surge of water, mud and debris to submerge parts of the country on August 26.
The devastation in the valleys below the glacier includes cross-border trade routes, roads, bridges, houses and other infrastructure which was swept away.
Rescuers in Nepal have retrieved 1,385 bodies, while around 5,130 people remain missing, the country's disaster agency said on Friday. In Tibet, the toll is 43 dead and 519 missing, according to Chinese state media.
The combined toll is 1,428 people dead and more than 5,649 missing, including around 800 foreigners, among them tourists and pilgrims.
Eight Australians who were originally declared missing in the flood have been found, with 35 still unaccounted-for.
Nepal's leaders are asking wealthier countries and global agencies for financial help in the wake of the floods, arguing the reconstruction costs show how climate change hits poor countries which do little to cause it.
The Nepal government is finalising a report detailing the extent of the damage, losses and funding requirements for temporary shelters, schools and essential infrastructure, officials said.
A UN preliminary assessment estimated building damage from Nepal's floods at $US158 million ($220 million) alone, warning that total losses — including damage to roads and bridges, agricultural land and humanitarian costs — would be far higher.
Prime Minister Balendra Shah said earlier that Nepal must "strongly raise" with the international community the disasters it has experienced as a result of climate change.
He is expected to take his first foreign trip as leader to address the UN General Assembly on the issue this month.
Nepal's disaster management chief Dharam Raj Uprety told Reuters the estimated cost will be shared with the World Bank and Asian Development Bank, along with the embassies of countries and blocs including the United States, Britain, India, China, Japan and the European Union.
Nanimaya Senchuri was one of many in Nepal who lost their farmlands in the floods, buried under mud and debris. She was inside her house, which she shares with her daughter, when the Trishuli River came crashing down nearby. As a result, she lost two large plots of farmland, her paddy crop and her banana plantation almost ready for harvest. The farm not only provided food for Ms Senchuri and her family, but was also her source of income. She was not sure whether she, and everyone else affected by the natural disaster, would receive compensation needed to rebuild farms and livelihood.
Nepal, a largely rural nation of 30 million people, contributes a fraction of global greenhouse gas emissions compared to industrialised nations. While the exact cause of the glacial collapse is unclear, climate change is causing glaciers to melt worldwide — increasing the risk of such disasters. Scientists say glaciers in the Himalayas, the world's highest mountain range, are melting faster as global temperatures rise.
Nepalese officials have publicly framed the disaster as an example of the disproportionate impact of climate change on poor countries. Nepal expects global agencies and other partners to "recognise this kind of event and take accountability on that" — though it is not for the country to dictate who should contribute how much — Prakash Pokhrel, a geologist for the National Disaster Risk Reduction and Management Authority said.
"We need not say what is causing climate change because you already know why climate change is happening and who is contributing the most to it," Mr Pokhrel said.
China accounts for roughly a third of global emissions, with the United States and Nepal's other neighbour India also among the world's biggest emitters.
China is willing to provide assistance within its capacity for Nepal's post-disaster reconstruction, foreign ministry spokesperson Guo Jiakun said on Thursday. Mr Guo said Beijing had immediately extended assistance to Nepal, while rescue and relief work was ongoing back home on its side of the border. "We believe that under the leadership of the Nepalese government, the Nepalese people will be able to overcome the disaster and rebuild their homes at an early date," he said at a regular news briefing.
