US President Joe Biden fears that Hurricane "Ian" has claimed numerous lives in the state of Florida.

"This could be the deadliest hurricane in Florida history," Biden said Thursday in Washington during a visit to the US Federal Emergency Management Agency (FEMA) headquarters.

"The number of victims is still unclear, but we are hearing the first reports of possibly significant loss of life." There was initially no official information on the number of possible fatalities.

The situation is still dangerous, warned Biden.

"We continue to experience deadly rains, catastrophic storm surges, flooded streets and houses," he said.

"We see millions of people without power -- and thousands sheltering in schools and community centers." These people wondered what was left of their homes, or if they would have homes at all.

The head of the civil protection agency Fema, Deanne Criswell, said: "Hurricane "Ian" will be a storm that we will be talking about for decades."

"Ian" made landfall on Wednesday as one of the strongest hurricanes in Florida's history and caused major damage there.