Nepal's earthquake reconstruction agency has increased by more than $1 billion its estimate of the money needed to rebuild nearly 1 million houses damaged by a powerful earthquake last year.

The Reconstruction Authority said in a report that $7.86 billion will be required, up from the $6.69 billion estimated last year by the government.

The head of the agency, Sushil Gyewali, said Thursday that the new estimate is the result of a detailed assessment of houses damaged by the magnitude-7.8 earthquake.

Foreign governments and donor agencies have already pledged $4.1 billion in financial help for reconstruction from the April 2015 quake, but progress has been greatly delayed and millions have been left without their homes.