Authorities have said they are making progress in the painstaking search for victims of the building collapse in Florida last month.

Miami-Dade County mayor Daniella Levine Cava said that 90 deaths have now been confirmed in the collapse of the 12-storey Champlain Towers South in Surfside, up from 86 a day before.

Among them are 71 bodies that have been identified, and their families have been notified, she said. Some 31 people remain listed as missing.

Ms Levine Cava said the search has resulted in the recovery of more than 6,350 tonnes of debris.

Surfside mayor Charles Burkett stressed not only the speed of the recovery work but also the care that rescue workers are taking in peeling back layers of rubble.

“The work is so delicate that we’re even finding unbroken wine bottles,” he said.

An Israeli search and rescue team arrived in South Florida shortly after the building collapsed on June 24. The team was heading home yesterday after an emotional send-off in Surfside.

During a ceremony on Saturday, Ms Levine Cava thanked the battalion for their “unrelenting dedication”.

Members of the task forces that have been searching the site 24 hours a day since the collapse lined the street, bidding farewell to the Israelis.

While authorities have concluded that there was “no chance of life” in the remaining rubble, the pressure remains for search crews to find victims so families can lay their loved ones to rest.

Miami-Dade County fire chief Alan Cominsky said it was not possible to pinpoint the date that the search and recovery effort would end.

Heavy machinery was removing debris, he said, while on the rubble pile from the collapse itself, there is “hand-digging” going on. “It’s a slow process,” he said.

Searchers have worked through Florida’s intense summer heat, and in pouring rain. They paused operations as officials made plans to implode the still-standing portion of the tower on July 4.