A Pakistani official says two military helicopters will again try to fly four Spanish rescuers to search for a missing pair of European climbers on Nanga Parbat.

Italian Daniele Nardi and Briton Tom Ballard, whose mother died on K2 in 1995, have been missing for almost a week.

Karrar Haidri, secretary of the Alpine Club of Pakistan, said on Monday that Spaniard Alex Txikon and his three colleagues, including a physician, who are going to try and help find the missing climbers on "Killer Mountain," will join Pakistani mountaineer Ali Sadpara who is already at base camp.

Bad weather on Sunday foiled the rescuers' drop off.

Italian ambassador Stefano Pontecorvo said in a tweet he hopes the rescuers will be able to fly to search for Nardi and Ballard.