The US President Donald Trump is to give US$1m of his own money to help people hit by Storm Harvey.
The storm has devastated parts of Texas and Louisiana.
Rescuers have begun door-to-door checks of tens of thousands of Houston homes, searching for victims left behind in the flood waters.
At least 38 people have been killed, including a family of six whose van was swept off a Houston bridge.
White House spokeswoman Sarah Huckabee Sanders told reporters Mr Trump wants to help like so many others.
"I'm happy to tell you that he would like to join in the efforts that a lot of the people across this country do - and he's pledging a million dollars of personal money to the fund".