The death toll in Indonesia's twin quake-tsunami disaster passed 1,400 yesterday, with time running out to rescue survivors and the UN warning of "vast" unmet needs, reports AFP from Wani.

National disaster agency spokesman Sutopo Purwo Nugroho said the number of dead had risen to 1,407 across four areas around the ravaged seaside city of Palu, and 519 bodies had been already buried.

Authorities set a tentative deadline of Friday to find anyone still trapped under rubble, at which point -- a week after this devastating double disaster -- the chances of finding survivors will dwindle to almost zero.

Government rescue workers are focusing on half a dozen key sites around the city -- the Hotel Roa-Roa where up to 60 people are still believed buried, a shopping mall, a restaurant and the Balaroa area where the sheer force of the quake turned the earth temporarily to mush. At least 150 people are unaccounted for beneath the rubble, officials said.

According to the UN's humanitarian office almost 200,000 people need urgent help, among them tens of thousands of children, with an estimated 66,000 homes destroyed or damaged by the 7.5-magnitude quake and the tsunami it spawned.

Despite the Indonesian government urging foreign rescue teams to "stand down" because the crisis was in hand, residents in hard-hit, remote villages like Wani in Donggala province say little help has arrived and hope is fading.

"Twelve people in this area haven't yet been found," Mohammad Thahir Talib told AFP.

"In the area to the south, because there hasn't been an evacuation we don't know if there are bodies. It's possible there are more," the 39-year-old said. In Geneva, the United Nations expressed frustration at the slow pace of the response.

"There are still large areas of what might be the worst-affected areas that haven't been properly reached, but the teams are pushing, they are doing what they can," Jens Laerke, from the UN's humanitarian office, told reporters late Tuesday.

The World Health Organization has estimated that across Donggala, some 310,000 people have been affected by the disaster.

Survivors are battling thirst and hunger, with food and clean water in short supply, and local hospitals are overwhelmed by the number of injured. Officials on the ground said that while the government was now inviting offers of help, there is still no "mechanism for this to be implemented".

Landing slots at Palu airport are snapped up by the Indonesian military, although it was expected to be open to commercial flights from 7:59am on Thursday.