Britain’s Queen Elizabeth II has said she is “deeply saddened” by the devastation caused by Hurricane Harvey, one of the most destructive storms in US history.

The monarch and her husband, Prince Philip — the Duke of Edinburgh, sent their condolences to the families of the 39 people known to have died in Texas in a message to US President Donald Trump. The death toll has since risen to 47.

“I was deeply saddened to learn of the loss of life and the devastation following the recent terrible floods caused by Hurricane Harvey,” the message from Buckingham Palace said.

“Prince Philip and I send our sincere condolences to the victims of this disaster, to those who have lost loved ones and to those who have seen their homes and property destroyed,” the message said.

Tens of thousands of people have been homeless in widespread floods caused by tropical cyclone Hurricane Harvey.

The US Federal Emergency Management Agency said about 364,000 people had already sought federal emergency aid because of the hurricane.

The storm initially made landfall as a Category 4 hurricane in Texas on August 25 before going back out to sea.

It became a tropical storm for days, flooding Texas cities including Houston before moving on to the neighbouring state of Louisiana.

Mr. Trump is proposing an initial $5.9 billion for recovery efforts but the Texas authorities say the state might need more than $125 billion dollars.