"Great coordination between agencies at all levels of government. Continuing rains and flash floods are being dealt with. Thousands rescued," Trump tweeted Sunday morning. In a separate tweet, he said that "many people are now saying that this is the worst storm/hurricane they have ever seen. Good news is that we have great talent on the ground."

As Harvey continues to threaten millions on the southeast Texas coast with downpours and heavy flooding, the Trump administration moved to show the public they are addressing a catastrophic storm that could become a defining moment for his presidency.

On Sunday, as the President returned to the White House from Camp David in Maryland, White House press secretary Sarah Huckabee Sanders announced that the President will travel to Texas on Tuesday, though she did not specify a location or further details of the trip.

"We are coordinating logistics with state and local officials, and once details are finalized, we will let you know," Sanders said. "We continue to keep all of those affected in our thoughts and prayers."

In a series of tweets prior to departing Camp David, Trump praised the way officials are handling the storm. The White House also released details of a Sunday morning teleconference that Trump and Vice President Mike Pence -- who changed travel plans to remain in Washington and monitor the storm -- held with members of the President's Cabinet.

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"President Trump continued to stress his expectation that all departments and all agencies stay fully committed to supporting the Governors of Texas and Louisiana and his number one priority of saving lives," Sanders said in a readout of the meeting.

Harvey made landfall late Friday between Port Aransas and Port O'Connor as a Category 4 hurricane and battered the southeast Texas coast with 130 mph winds. The storm has caused catastrophic flooding across south and southeast Texas, and the National Weather Service said Sunday that the rainfall from Harvey could reach 50 inches in some places, the highest-ever recorded rainfall in the state.

The impact of the storm, the head of the Federal Emergency Management Agency said Sunday, could be felt for a long-time to come.

"FEMA is going to be there for years," the agency's administrator, Brock Long, told CNN's Jake Tapper on "State of the Union, saying that "this disaster is going to be a landmark event."

Bracing for a sustained response

That reality means the Trump administration's response to Harvey will be an ongoing test.

President George W. Bush's slow response to Hurricane Katrina in 2005, punctuated by his praise of his FEMA director Michael Brown, whom Bush touted as doing a heck of job, was a defining moment for him and struck a blow from which his presidency, already damaged by the Iraq War, never recovered. In 2012, Superstorm Sandy battered the shores of New Jersey one week before the November election, and both then-President Barack Obama and New Jersey Gov. Chris Christie received plaudits for their response to the storm.

Deftly handling the response to the hurricane and its impact could give the Trump administration the opportunity to snatch back news cycles that have been dominated by reaction to the President's comments in the aftermath of the deadly clashes in Charlottesville, Virginia, and rifts between the White House and Republicans on Capitol Hill, including Senate Majority Leader Mitch McConnell, Tennessee Sen. Bob Corker and Arizona Sen. Jeff Flake.

On Friday night, as Harvey barreled toward Texas, the White House fueled a brand-new controversy when Trump pardoned Joe Arpaio, the controversial former Arizona sheriff convicted of criminal contempt. In the first pardon of his presidency, Trump did not follow his predecessors' practice of consulting with lawyers at the Justice Department before announcing his decision — a move that drew criticism from civil rights groups and Democrats as well as both of Arizona's Republican senators, Flake and Sen. John McCain. On Saturday, The Washington Post reported that Trump had asked Attorney General Jeff Sessions about halting the criminal case against Arpaio earlier this year.

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Tom Bossert, Trump's homeland security adviser, told ABC's George Stephanopoulos on Sunday that there had been "some disproportionate coverage of it" and that he was focused on the people impacted by Harvey.

Throughout the weekend, it was clear that the administration was working to demonstrate its aggressive response.

Those efforts began Friday, when Bossert briefed reporters at the White House prior to Trump's afternoon departure to Camp David. As he outlined the federal government's preparations for handling the story, Bossert expressed confidence about the government's ability to respond to storms.

"This is right up President Trump's alley, " Bossert said Friday. "Not only has he shown leadership here, but his entire focus has been on making America great again."

A focus not just on Harvey

After pardoning Arpaio Friday night, Trump focused his weekend tweets on Harvey — but not exclusively so.

He began Sunday morning with a tweet endorsing a book by David Clarke, the Milwaukee County sheriff who supports Trump, and another one needling Missouri Sen. Claire McCaskill ahead of his planned trip Wednesday to Springfield, Missouri. He also tweeted about NAFTA and the wall he wants to construct at the US border with Mexico.

"With Mexico being one of the highest crime Nations in the world, we must have THE WALL. Mexico will pay for it through reimbursement/other," the President tweeted.

Trump's response to the storm will be closely watched in Washington and around the country due to both his lack of governing experience and inability, so far, to seize the opportunity to unite the country in moments of crisis.

The White House is still dealing with the fallout of Trump's response after the bloody clashes in Charlottesville that left one woman dead. The President has been criticized both within and outside his party for his response, in which he blamed the unrest "many sides."

Sanders said Sunday that Trump would travel to Texas on Tuesday, though it is unclear where in the state he will go and what the trip entails. The President himself earlier in the day tweeted that he planned to make such a trip "as soon as that trip can be made without disruption." The focus, he added, "must be life and safety."

Asked earlier Sunday whether a presidential visit to Texas made sense right now, Texas Gov. Greg Abbott, a Republican, told ABC that "it depends," given the fact that the storm's impact is so unpredictable.

"As you know, we had a hurricane hit around the Corpus Christi area that is now moving northeast, and is over closer to the Houston area. And it depends on where he goes," Abbott said. "We are already, for example, involved in the cleanup process in Corpus Christi. If the President were to visit there, it wouldn't hinder any efforts."

Ultimately, Abbott, concluded, time will tell.

"We'll just have to wait and see where the storm goes, understanding that this entire storm has been very unpredictable in its movement," he added. "And I couldn't tell you right now where it will be in two days."