US President Donald Trump reassured residents of Kerrville, Texas, that the government would help rebuild after floods hit the central part of the state last week, killing 120 people.

The president and First Lady Melania Trump met on Friday with local officials on the ground – standing in front of an upended tractor trailer – and surveyed the damage.

“I’ve never seen anything like it,” Trump said after taking a tour of the devastation.

More than 12,300 volunteers have gathered to help search for the 161 people still missing statewide. Officials said volunteers have been working 10 hours a day.

Trump told officials at an afternoon roundtable that he and the first lady were in town to “express the love and support, and the anguish of our entire nation”.

The first lady, who ordinarily keeps a low profile, joined the tour of the devastation. She said she hugged and prayed with families of the victims during her visit.

“My deepest sympathy to all of the parents who lost beautiful young souls,” she said. “We are grieving with you. Our nation is grieving with you.”

She also promised to visit again.

In the wake of the deadly tragedy, questions have been raised about whether adequate warnings were provided and why some weren’t evacuated ahead of the deluge.

“Only an evil person would ask a question like that,” Trump responded when the topic came up Friday, saying it’s easy to sit back and wonder what could have happened.

The Guadalupe River levels, which submerged homes, roads and cars, caught many by surprise.

The catastrophe unfolded before daybreak last Friday as the river rose 26ft (8m) in the span of just 45 minutes. Young children and staff at summer camps along the river were asleep as weather alerts went off.

Search crews in Texas are still sifting through debris for scores of missing people. Authorities have said they will not relent until everyone is accounted for.

Experts have said there were a number of factors that led to the tragic floods in, including the pre-dawn timing, the location of some homes and the extreme weather.