Nepal’s government is led by a 36-year-old former engineer turned rapper, Balendra Shah, who swept to power just months ago on the back of youth anger over an economy ravaged by corruption and mismanagement.

Now, he and his fledgling government face a herculean test after devastating floods ravaged his impoverished country. A majority of Mr. Shah’s 17 ministers are under 40, and they were still finding their way around governance before the disaster struck.

Five days after a deluge caused by a glacier breaking in the Himalayas flooded northern Nepal and parts of Tibet, the number of missing in Nepal jumped Monday to more than 4,700 and the death toll rose past 900 as the scale of the disaster became more apparent.

Mr. Shah has not spoken publicly since the floods. Rather, he has visited places affected by the disaster, wearing his trademark double-breasted suit, black shades and white sneakers. He has led meetings with his ministers, who have also been in the field overseeing emergency efforts.

“There can be no greater pain than losing loved ones, homes and livelihoods,” Mr. Shah, who prefers communicating on social media to taking questions from reporters, said in a statement on Facebook on Sunday. He added, “Without making excuses, we have mobilized the entire state machinery on a war footing and are working around the clock to save lives and provide relief to every citizen in the affected areas.”