Seoul: The families of South Korean workers missing after a catastrophic flash flood in Nepal urged authorities on Friday to secure helicopter access for a search, saying rescuers were losing critical time more than ‌48 hours after the ⁠disaster.The ⁠nine missing workers, employed by Doosan Enerbility and Korea South-East Power, were working on a major hydropower project hit by Wednesday's glacier-triggered flash flood."Our only demand is to get helicopters in the air as soon as possible," ​relatives of Doosan Enerbility employees told reporters, according to the company and Yonhap News Agency, expressing frustration over what they described as a lack of visible progress despite assurances from officials.Also Read: Nepal declines foreign rescue help, South Korea says it is 'negotiating'The ​families said they had not received sufficient information about the ⁠missing workers' ‌whereabouts or the circumstances of the disaster, and called for search footage ​and other updates to ​be shared promptly.They also urged South Korea to press Nepalese ⁠authorities through diplomatic channels for more active support.A South Korean rapid ​response team that arrived in Kathmandu on Thursday night was still ​awaiting flight clearance to travel to the affected area, South Korea's Foreign Ministry said. Nepal's military had restricted private helicopter operations over concerns of further flooding, Yonhap said.Earlier on Friday, the ministry said Nepal had indicated it was not yet planning to accept foreign rescue teams and that it was holding discussions on the matter. Nepal's Foreign Ministry said on Friday that ‌it did not need foreign assistance for search-and-rescue operations and that it was managing the rescue efforts.South Korean President Lee Jae Myung ordered on Thursday an all-out ​response to ​the disaster.Doosan Enerbility CEO ⁠Jeong Yeon-in said on Thursday the company was working closely with relevant authorities and would "make every possible effort" to rescue employees who remained out of contact.Also Read: PM, ministers pledge a month's salary to relief fund; Kathmandu to buy 25,000 MT of fertilisers from New DelhiYoon Jang-hyun, head of new growth ​business at Korea South-East Power, said the company would focus on searching for its employees and assessing conditions at the site, adding that it would mobilise all its capabilities to secure their safe return.The nine South Korean workers still unaccounted for include six Doosan Enerbility employees and three employed by Korea South-East Power, the Yonhap News Agency said.