Trump addressed the flooding from Hurricane Imelda in Houston, telling a rally for Indian Americans he had a message for the city, "we love you, we support you."
The storm and associated flooding is blamed for at least five deaths.
Imelda damaged at least 10 schools in Harris County, which surrounds Houston.
Dozens were rescued Saturday from Huffman, a neighborhood northeast of Houston, as floodwaters rose.
Beaumont to the east confirmed it saw over 40 inches of rain, forcing the closure of many schools.