President Donald Trump is making an all-out push to show the federal government's responsiveness to the massive storm that has lashed the Texas coast and caused catastrophic flooding.
Trump will travel to Texas on Tuesday for briefings on the federal government's work to help the state recover from Harvey's devastation.
The storm marks the first time Trump has been tested by a major natural disaster at the start of his administration.
The president was scheduled to get briefings on the relief efforts in Corpus Christi, Texas, and later meet with state officials at the emergency operations center in Austin.
The president will be joined by first lady Melania Trump.
Trump spent most of the weekend at the presidential retreat at Camp David, Maryland, and convened his Cabinet by telephone during the weekend. He tweeted on Sunday a promise of a Texas visit "as soon as that trip can be made without causing disruption" - later announced by the White House as Tuesday.
Texas Gov. Greg Abbott, a Republican and Trump ally, loaded heavy praise on the president and the federal government, describing it as an "A-plus" effort.
"I've got to tell you, I give FEMA a grade of A+, all the way from the president down," Abbott said. "I've spoken to the president several times, to his Cabinet members, such as secretary of homeland security, such as the administrator of FEMA, such as Tom Price, the secretary of health and human services."
The devastating storm has dumped more than two feet of rain, sending thousands of people in Houston to rooftops for rescue and prompting a warning from Federal Emergency Management Agency director Brock Long of a "landmark event" that could require years to get damaged areas back on track.
Harvey made landfall along the Gulf Coast on Friday night as a Category 4 storm near Corpus Christi, and moved northeast along the Texas coast over Houston. Abbott said he expected heavy rain "for days to come."
The governor commended Mr. Trump for being "extremely professional, very helpful" in moving quickly to grant his request Friday for an immediate disaster declaration, which triggers additional federal assistance to aggrieved areas.
The Associated Press contributed to this report.