Nepal has cleared more than 300 mountaineers to climb Mount Everest this year after they had to abandon last year's efforts when an ice avalanche killed 16 guides in the mountain's deadliest disaster.

The head of Nepal's tourism department, Tulasi Gautam, says the government is extending last year's permits without charging new fees.

He said the extended permits could be used at any time through 2019, and that the climbers can climb individually or join a group.

The three-month climbing season for Everest, the world's tallest mountain, begins in March. Nepal also pledged recently to improve weather forecasting, security and rescue efforts, and has cut climbing fees this year to $11,000 per climber from $25,000.