Sumi Adhikari has been confirmed as one of the 41 Australians missing in the disaster, with her husband Nava Pandey vowing "every hour matters" in the search operation.
Chinese and Nepalese authorities warn further flooding could occur, complicating rescue efforts and posing a risk to local communities.
Nava Pandey has been desperately seeking information about Ms Adhikari's whereabouts since arriving in Nepal.
Speaking with AAP on Saturday, he still has no clear or official information about his wife or the other members of her group who were on an Isha Foundation pilgrimage to the region.
"Based on the CCTV footage that has emerged and their last known location in the Gyirong area, our most urgent request is for an immediate and thorough search operation in that location," Mr Pandey said.
Mr Pandey, who remains in Kathmandu, said he had heard the Nepalese Army could be heading to the area today.
"We urgently request official confirmation and close co-ordination between the Nepalese and Chinese authorities," he said.
Australian Defence Force member Karan Bhardwaj and Brisbane friends Arpan Mithalal Kothari and Bhavin Raval are among the missing.
The trio was travelling near the Nepal -Tibet border with Kailash Journeys as part of a tour group when the flooding hit.
Mr Bhardwaj has been described as a proud defence force member, a beloved father of one and brother, and a friend to many.
"Our family is desperately waiting for news," family member Jen Nai told AAP.
"We are praying with everything we have that Karan and his friends are safe and that they will be brought home."
Ms Nai has not been in contact with her brother-in-law since he sent a group photo, while Mr Raval's wife is yet to receive any news about his whereabouts.
Assistant Immigration Minister Matt Thistlethwaite confirmed 41 Australians were still missing as of Saturday morning.
At least 579 people in Nepal and seven in China's Tibet are dead, with the number missing in Nepal almost doubling to 1924, the country's disaster authority said on Friday.
More than 550 are missing in Tibet's Gyirong County, including 260 foreigners, according to Chinese state broadcaster CCTV.
Mr Thistlethwaite told reporters DFAT staff were in Kathmandu making contact with as many Australians as possible.
He said families were desperate for news about loved ones
At least 10,000 homes had been destroyed, with many roads cut off due to the extensive flood damage, Mr Thistlethwaite said.
"Roads have been blocked, homes have been destroyed, communications infrastructure has been knocked out and power is down, so it's very difficult to get information in and out of the region," he said.
Nepal has accepted a $5 million humanitarian aid package from Australia.
NSW Premier Chris Minns told reporters on Saturday he was devastated by the disaster.
"Literally hundreds of people have lost their lives, potentially thousands. I know that there are many who are still missing, including Australians right now," he said.
"Our heart bleeds for them."
NSW mother of two Reshma Patel was also making a pilgrimage with the Isha Foundation when the floods hit.
Her last known location was an immigration office along the Nepal-Tibet border, captured in viral footage.
"She was inside the big building, which you can see in all the videos that had been hit hard by the floods at the border," family friend Chin Valsan told AAP.
While search and rescue operations, aided by Australian officials, are ongoing, charities have banded together nationally to raise funds.
The Australian Red Cross announced all donations to its global emergency fund from Thursday would go to Nepal, while World Vision Australia has launched a dedicated appeal.
UNICEF is appealing for $US17.2 million to fund its emergency relief and recovery efforts, including for the estimated 17,000 children affected.
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