Updated at 3:15 p.m. Jan. 7: Revised to include additional comments from Texas lawmakers.

WASHINGTON — President Donald Trump will dramatize his demands for a massive barrier in the Southwest with a visit to the U.S.-Mexico border on Thursday as he ramps up pressure on Congress to fund the project.

He also plans a rare prime-time address to the nation at 8 p.m. Dallas time Tuesday about what he called the "Humanitarian and National Security crisis on our Southern Border" — a much disputed characterization.

The announcements came on Monday, Day 17 of a partial government shutdown that began Dec. 22 over Trump's demands for a wall.

The president's likely destination is Texas. The FAA on Monday posted a flight restriction notice for McAllen, suggesting that's where Air Force One would be heading.

I am pleased to inform you that I will Address the Nation on the Humanitarian and National Security crisis on our Southern Border. Tuesday night at 9:00 P.M. Eastern. — Donald J. Trump (@realDonaldTrump) January 7, 2019

President @realDonaldTrump will travel to the Southern border on Thursday to meet with those on the frontlines of the national security and humanitarian crisis. More details will be announced soon. — Stephanie Grisham (@PressSec) January 7, 2019

Rep. Vicente Gonzalez, a McAllen Democrat who, like many other members of Congress from Texas, strongly opposes Trump's proposed wall, asserted that if the president wants to dramatize a crisis, he won't find it in the Rio Grande Valley.

McAllen, he noted, "has experienced some of the lowest crime rates in 30 years. ... If the president does visit McAllen, Texas, he should feel free to walk around and support our local businesses. After all, it is safer to walk around McAllen than it is D.C."

McAllen would be an interesting choice for a visit.

That's where first lady Melania Trump flew in May, at the height of the family separation crisis triggered by her husband's new policy of pressing criminal charges against any adult caught crossing into the country illegally. That policy, which the president and aides falsely characterized as a continuation of Obama era policies, forced federal authorities to put thousands of migrant children into detention centers separate from their parents, because of caps on how long children can lawfully be kept in jail.

Melania Trump's choice of outerwear for that trip — a jacket that read "I really don't care. Do U?" — set social media abuzz, generating speculation about whether she was trying to embarrass her husband by putting a spotlight on the issue of child separations.

U.S. Rep. Henry Cuellar, a Laredo Democrat, also pushed back on the notion that security at the border amounts to a crisis of any sort.

"There is no national emergency at the U.S.-Mexico border," he said, citing the most recent FBI crime data as "proof that the area is safe and open for business."

"Do we need more border security? Yes," he said, "but it has to be common-sense border security that does not include a 14th-century solution called the wall."

But U.S. Rep. Michael Burgess, a Republican from suburban Dallas, called the situation in South Texas "urgent" and a "national emergency."

I’ve traveled to #McAllen, TX many times since 2014, and it’s only right for President @realdonaldtrump to see firsthand the urgent situation on the southern border. What the last Administration labeled a humanitarian crisis is now a National Emergency with consequences. https://t.co/dUtWrVs5i3 — Michael Burgess, MD (@michaelcburgess) January 7, 2019

Trump triggered the shutdown by digging in on a key campaign promise — a "big, beautiful wall" —after initially agreeing to a deal that would have kept the government open without providing any funding for wall construction.

He is now demanding $5.7 billion, up from $5 billion.

Trump threatened on Dec. 28 to "close the Southern Border entirely" if Democrats didn't authorize funding for the wall. The disruption to trade would hit Texas and the national economy hard, though the president almost certainly lacks the authority to end border crossings, for U.S. citizens especially but also for foreigners with visas or other authorization.

He has also threatened to declare a national emergency and divert Pentagon funds to barrier construction. His authority to take such a step is much in dispute, and that move would trigger legal challenges.

Vice President Mike Pence told reporters at the White House on Monday that the White House counsel was researching the issue.

.@VP Pence tells reporters White House Counsel’s office is looking into the legality of declaring a national emergency over the border wall demand — Jeff Mason (@jeffmason1) January 7, 2019

Since Trump took office nearly two years ago, no part of the border has been walled off that didn't already have barrier in place. And despite his oft-repeated campaign promise that Mexico would pay for the project, he has presented no plan that involves any funding besides revenue from U.S. taxpayers.

A $5 billion outlay would be enough to upgrade 115 miles of existing fence and add barrier along 100 miles of border that isn't already fenced, federal officials have said.

Ahead of the shutdown, Trump agreed to sign a budget without wall funding. He reneged amid an uproar from conservative commentators, and publicly vowed to take full blame for any shutdown that might ensue, though he has since sought to shift blame.

Democrats took control of the House on Thursday. Their new speaker, Nancy Pelosi, quickly stepped up pressure on Trump and Senate Republicans by pushing legislation that would fund the shuttered parts of the government through September and allow a month for talks on border security.

Staff-level meetings over the weekend yielded no apparent progress.

On Sunday news shows, acting White House Chief of Staff Mick Mulvaney argued that Trump had given ground by agreeing to back away from his insistence on an opaque, solid wall.

"If he has to give up a concrete wall, replace it with a steel fence ... so that Democrats can say, 'See? He's not building a wall anymore,' that should help us move in the right direction," Mulvaney said.

But, he added, that hasn't been good enough to sway the other side.

"I'm not making this up," Mulvaney said. "We had a two-hour meeting over whether or not a 20-foot-high, 30-foot-high steel-bollard, steel-slat barrier is a wall or not. That's how broken I think some of these discussions are."