The US has offered help to Pakistan in searching 135 soldiers and civilians buried under snow following an avalanche in the country's Siachen region.

The avalanche hit an army camp near Skardu district at 6am on Saturday. Army Chief Gen Ashfaq Parvez Kayani has visited the site to personally supervise the rescue work.

The US embassy in a statement expressed "deep concern for the Pakistani soldiers" and said "the US is ready to assist Pakistan in search, rescue, and recovery operations".

Kayani said such an avalanche never occurred in the last 20 years in Pakistan. He said the army has always risen to the occasion and will come through this challenge as well.

The rescue operation was underway on the second day at the site Sunday, with sniffer dogs, helicopters and troops on ground, Xinhua reported.

The met office has forecast snowfall in the area this week that may hamper the rescue work.