There's never been anything like it, says Prez Trump

"It's the biggest ever, they are saying it is the biggest, it's historic," Trump said, addressing a White House press conference on Monday, a day before he travels to the Lone Star State with First lady Melania Trump. "There's probably never been anything like this," Trump said of Tropical Storm Harvey, which hit the Gulf Coast at the weekend and inundated the Houston region.

"I've heard the words 'epic,' I've heard 'historic.' That's what it is," he added. The US leader earlier indicated his team had already been in contact with Congressional leaders to discuss relief for the millions of people affected by tropical storm Harvey, which is barrelling along the Texan coast toward Louisiana.

"We're dealing with Congress," Trump said, speaking from the Oval Office, "as you know it's going to be a very expensive situation. We want to take care of the people of Texas and Louisiana when that happens." Since making landfall, Harvey has soaked Houston, America's fourth largest city and the capital of the country's vast energy industry.

Trump has been eager to show he is on top of the situation, and that he will not make the same mistakes as previous presidents in botching the federal response.

"Things are being handled really well, the spirit is incredible of the people and the coordination between all of the different services, as you know, has been going very well," he said.

Trump's trip to Texas comes much more quickly than other presidents may have dared. Along with a high-impact presidential trip comes the risk of hampering recovery efforts and tying up resources.

Meanwhile, the remnants of deadly Hurricane Harvey spilled toward Louisiana on Tuesday with more potentially disastrous flooding and emergency evacuations as President Trump planned to survey the ongoing devastation in stricken Texas. The death toll in Texas had reached nine, officials said, but they said it could rise as authorities pursue reports of people apparently lost in the torrential downpours unleashes by Harvey since Friday. In Montgomery County, north of Houston, police said a man was presumed drowned after attempting to swim across fast-moving flood wash.

The storm clouds continue to drench the region with an unprecedented deluge — reaching 43 inches since Friday in South Houston and surpassing 40 inches in several other places in around the city, the National Weather Service reported.

For Houston, the rainfall amounts since June 1 reached 50.16 inches — more than the annual average rainfall of 49.77 inches. In Louisiana, rescue teams near Lake Charles near the Texas border evacuated hundreds of people as floodwaters crested river banks and levees. Flash flood warnings and watches were in effect for much of the Lake Charles region as forecasters said up to 10 inches or more rain could fall before the storm is done. New Orleans was under a tornado and flash flood watch until Thursday.

Harvey is moving toward the northeast, with its center expected to be just off the middle and upper Texas coast through Tuesday night, the National Hurricane Center said on Tuesday morning.

After that, the storm is forecast to move inland on the northwestern Gulf Coast on Wednesday.

Forecasters say more than a foot of rain is still expected to fall through Friday over parts of the Texas coast and Louisiana, and the National Weather Service warned Tuesday of potential flooding in southern Mississippi as well as southeastern Louisiana.

Trump on Monday declared "emergency conditions" in Louisiana. Texas Governor Greg Abbott said that recovery from the catastrophic hurricane Harvey will be "long and slow" since it was "one of the largest disasters America has ever faced", the media reported.