The death toll is likely to rise, with some 18 people still missing, after floods hit mostly farming communities in the country's southern plains and remote western hills, said Dhakal.
"The death toll is likely to increase as the areas affected are remote and we are still gathering information," Dhakal said.
Fourteen out of the country's 75 districts have been declared disaster-hit by the government following the floods which have also damaged more than 180 homes, officials said.
The head of the government, former chief justice Khil Raj Regmi, visited the worst-hit Darchula district on Thursday, where more than 100 homes have been damaged by a flooding river.
The government has decided to deliver a relief package of 40,000 rupees ($420) each to the victims. On Wednesday, a helicopter carrying blankets and medicines was sent to the disaster-hit region.
Hundreds of people die every year from flooding and landslides during the monsoon season in Nepal.
The annual monsoon has also struck over the border in India, with landslides and floods leaving hundreds dead and thousands more people stranded.