Trump touts border wall in visit to Texas

President spoke extensively Tuesday during a trip to the U.S.-Mexico border -- days after he was cut off from supporters when his Twitter account was permanently suspended.

The president's remarks were notable in that he spoke – both in tone and content – as if he has accepted the end of his presidency is near.

He acknowledged that he would no longer be president on Jan. 20, and his speech to border security officials attempted to reflect on what he believes are his accomplishments as president.

Among them: His signature promise to build a wall and make Mexico pay for it.

"We can't let the next administration even think about taking it down," Trump said, referring to the barrier, although President-elect Joe Biden has said he would not dismantle existing barrier -- just stop further construction.

But Trump has fallen far short of his promise. During the 2016 campaign, he repeatedly said the U.S. needed 1,000 miles of wall along the southern border, and in the years since his election, he kept shifting the goalposts.

After signing a plaque commemorating the border wall, the president said he was overseeing the construction of the 450th mile of wall. But his administration has built just 47 miles of new wall along the border in places where no barrier had existed before -- instead beefing up the structures that largely proved ineffective at curbing illegal immigration.

Trump's administration has also built 33 miles of new "secondary wall" where no secondary barrier existed before -- walls much further back from the border line -- more than a mile in some places. It acts as a second line of defense for the U.S. Border Patrol.

The Trump administration has also replaced about 351 miles of wall along the border, as well as replaced about 21 miles of "secondary wall." This involves replacing old, outdated barriers – such as guard-rail fencing – with technologically advanced wall: 18-to-30 foot steel bollards, access roads, lighting and surveillance systems.

All of that together -- new primary wall, new secondary wall, replacement primary wall, and replacement secondary wall -- totals about 452 miles of barriers, all paid for with billions of U.S. taxpayer dollars.

As he had before, Trump presented the border barrier as a preventative measure from allowing COVID-19 to spread into the United States from the south.

He also warned a "tidal wave" of undocumented immigrants would head toward the United States if his immigration policies were reversed.

That contradicts what the commissioner of U.S. Customs and Border Protection, Mark Morgan, told ABC News a few weeks ago -- that the flow had slowed to "a trickle."

"Waves are starting to come up from 2,000 and 1,000 and 500 miles away," Trump said. "We see what's coming. And they're coming because they think it's gravy train at the end."

The president said migrant caravans should be called "the gravy train, because that's what they're looking for" - "the gravy."

Apart from posting video on his Twitter page on Thursday, the president had remained behind closed doors at the White House -- spending his final days in office out of the public eye.

In the wake of last week's riot at the Capitol, the president is facing renewed calls from congressional Democrats to be removed from office. The House is poised to pass an impeachment resolution this week charging the president with incitement of insurrection. If the House successfully impeaches Trump and the Senate convicts the president, he could be barred from seeking future public office -- even if Congress acts after he leaves office.

The wall, which became a pet project of the president and central focus of his failed campaign for reelection, could stand as a lasting legacy for Trumpism.

Rep. Vicente Gonzalez blasted Trump ahead of the visit to his district and urged elected officials not to join the president on his trip.

"Do not be fooled: President Trump does not care about the people of South Texas, this country, or the rule of law," Gonzalez, D-Texas, said. "This is a time for good ol' South Texas American pride to beam into our communities and to not allow ourselves to be used like an old rag by a modern day traitor."

The president spent about two hours on the ground in Texas. The West Wing has been building out a week of programming to highlight Trump's record, according to people familiar with the planning.

ABC News' Quinn Owen contributed to this report.