A home is shown as floodwaters from Tropical Storm Harvey rise, Aug. 28, 2017, in Spring, Texas.
A home is shown as floodwaters from Tropical Storm Harvey rise, Aug. 28, 2017, in Spring, Texas.

Tropical Storm Harvey is a monster who is showing no mercy to his victims.

Forecasters say the storm is slowly moving off the southeastern Texas coast back into the Gulf of Mexico, where it will suck up tons of additional moisture before making a second strike on the already flooded city of Houston.

Rescuers are working non-stop to look for people stuck inside their flooded homes or who have sought safety on their rooftops.

People push a stalled pickup through a flooded str
People push a stalled pickup through a flooded street in Houston, after Tropical Storm Harvey dumped heavy rains, Aug. 27, 2017.

Highways and interstates normally filled with cars have become impassable rivers.

Dirty brown water covers downtown Houston sidewalks which would normally be filled with officer workers, shoppers, and tourists.

Television pictures show a gloomy, apocalyptic-like scene — boatloads of flood victims being pushed along what is normally a busy highway with stranded cars and trucks emerging from the water. Others follow behind, wading through the waist-deep floodwaters as the rain continues to fall.

Of the rescues, Houston Mayor Sylvester Turner tells CNN "we're not going to stop until we reach every single person."

Turner said as of early Monday evening, 3,052 people have been rescued and 8,000 are in shelters. The mayor said there are three confirmed flood-related deaths in Houston. He said he hopes and prays that number will not rise.

Sgt. Chad Watts of the Louisiana Department of Wil
Sgt. Chad Watts of the Louisiana Department of Wildlife and Fisheries holds Madelyn Nguyen, 2, after he rescued her and her family by boat from floodwaters of Tropical Storm Harvey, in Houston, Aug. 28, 2017.

Volunteers have joined police, fire and medical crews, as well as the National Guard. 

Texas Governor Greg Abbott told reporters he has deployed the entire Texas National Guard — a total of 15,000 men and women.

Abbott heaped praise on local leaders along the Texas Gulf Coast, calling them "humane, courageous, and heroic." He said the way people got through the storm and that so many lives were saved is "remarkable."

Trump pledges help

President Donald Trump is pledging that "every asset at my command" will be available to Texas and Louisiana as they deal with catastrophic floods.

Joe Garcia carries his dog, Heidi, from his floode
Joe Garcia carries his dog, Heidi, from his flooded home as he is rescued from rising floodwaters from Tropical Storm Harvey, Aug. 28, 2017, in Spring, Texas.

Trump told a White House news conference Monday that people in flood-stricken areas can expect "very rapid action" from Congress to get the funding they need to clean up and rebuild.

"You're going to have what you need and it's going to go fast," the president reassured flood victims. He said he has spoken to many lawmakers who "feel for" Texans.

Trump will visit southeast Texas on Tuesday and says he may go back to Texas and Louisiana on Saturday to see that officials have all they need. He has already declared 18 Texas counties and parts of neighboring Louisiana a disaster area, making them eligible for federal help. The Texas governor has declared 54 counties as disaster areas, making them eligible for state aid.

Damage from the storm is expected to be in the tens of billions of dollars.

WATCH: FEMA Focusing on 'Life Sustaining' Mission

Trump said 8,000 federal workers are on the ground in Texas, including many with the Federal Emergency Management Agency (FEMA).

FEMA chief Brock Long told a Monday news conference that the agency is going to be in Texas "for several years."

"We're anticipating over 30,000 people being placed in shelters temporarily — to basically stabilize the situation and provide for their care. Next — we are ready — and already deploying life-essential commodities."

Long said FEMA is bracing for one of the longest periods of housing recovery ever seen.

Rescue boats fill a flooded street as flood victim
Rescue boats fill a flooded street as flood victims are evacuated during Tropical Storm Harvey, Aug. 28, 2017, in Houston.

More rain ahead

Houston and parts of southwestern Louisiana can expect as much as 50 more centimeters of rain through Thursday, along with high winds and possible tornadoes. The region has already seen more than 60 centimeters of rain in some places.

"While the hurricane-force winds have diminished — I want to stress that we are not out of the woods yet," said acting U.S. Homeland Security chief Elaine Duke. "Not by a long shot. Harvey is still a dangerous and historic storm."

Evacuees ride in a boat down Tidwell Road as flood
Evacuees ride in a boat down Tidwell Road as floodwaters from Tropical Storm Harvey rise in Houston, Aug. 28, 2017.

Duke said rivers in south Texas "won't crest until later this week."

Louisiana Governor John Bel Edwards said, "The storm is more or less stationary, but to the extent that it's moving, it's actually moving towards the east in our direction and that makes this, obviously, a dangerous situation for our state."

U.S. Weather Prediction Center lead forecaster Patrick Burke told VOA, "We've never seen a storm like this. We've never seen these rainfall amounts over such a large area, and so the damage is already catastrophic and unfortunately is going to continue to be catastrophic for days to come."

A car is submerged on a freeway flooded by Tropica
A car is submerged on a freeway flooded by Tropical Storm Harvey, Aug. 27, 2017, near downtown Houston, Texas.

With the storm bringing band after band of heavy rain over the region, the U.S. Army Corps of Engineers announced early Monday it was beginning the controlled release of water from two reservoirs in order to help prevent them from failing and to reduce the risk of further flooding.  The releases will continue for weeks.

Harvey was the strongest hurricane to hit the United States mainland in more than a decade.

But Trump said tragic times bring out the best of American strength and resolve.

"We will come out of this bigger, better, stronger than ever before," he said.

Kenneth Schwartz, Ken Bredemeier and Chris Hannas contributed to this report.