After pledging for years to construct a solid wall along the U.S.-Mexico border to combat illegal immigration, President Donald Trump appears to be backing away from that promise as he and his allies play down what the administration wants built - alternately referring to the planned wall as a fence, a "steel slat barrier" or a metaphor for border security.
The shift marks a tacit acknowledgment of retreat by the White House on one of its signature issues as it faces the reality of divided government in the new year and a partial government shutdown that is in its second week.
Trump has already altered his long-standing pledge that Mexico would pay for the wall, claiming earlier this month that a new trade deal with Mexico and Canada would cover the cost "just by the money we save," a notion dismissed by experts and for which the White House has offered no explanation.
Rep. Mark Meadows, R-N.C., a leader of the conservative House Freedom Caucus, defended the president on Monday, saying Trump "has embraced a number of options for border barriers," including a concrete wall in certain areas and steel slats or fencing in others.
"All have been considered as part of the solution," he said.
Trump has been sensitive to any criticism from his supporters, including in conservative media, that he is softening his stance on the wall, and some are saying they are concerned about any move away from building a solid barrier on the border.
"I absolutely want to build a wall in the sense that the president has described it all throughout the campaign and in the sense that I've described it in all of my 16 years in Congress," said Rep. Steve King, R-Iowa, an immigration hard-liner. "Wherever there's a wall built, it's been effective."
The debate over what constitutes a wall comes as Trump and Republican leadership are at odds with congressional Democrats on the issue of border security, with the impasse leading to a partial government shutdown that is unlikely to be resolved until Thursday at the earliest, when the new Congress convenes and Democrats take control of the House.
A Trump-backed spending bill passed by House Republicans on Dec. 20 included more than $5 billion in border-security funding that could be spent on a wall, but that measure has not gained traction in the Senate, where Democrats are resisting the president's demand.
On Monday, the president disputed an assertion by his outgoing chief of staff, John Kelly, that the White House has jettisoned plans for a concrete wall, claiming that the idea was "NEVER ABANDONED."
In morning tweets, Trump sought to blame the media for the discrepancy and said he still envisions an "all concrete" wall in some areas but that a "see through" barrier at the U.S.-Mexican border would be more appropriate in other areas based on what he's been told by "experts at Border Patrol.
"Makes sense to me!" he added.
In an interview published Sunday in the Los Angeles Times, Kelly was quoted saying that the current White House plan for a barrier is "not a wall."
"The president still says 'wall' - oftentimes, frankly, he'll say 'barrier' or 'fencing.' Now he's tended toward steel slats," Kelly said. "But we left a solid concrete wall early on in the administration when we asked people what they needed and where they needed it."
During his presidential campaign, Trump made his plans to build a "beautiful" solid border wall a central part of his platform.
"Did you ever see precast plank, for parking garages?" Trump said in Derry, New Hampshire, in August 2015, at the first town hall of his campaign. "So, you take precast plank. It comes 30 feet long, 40 feet long, 50 feet long . . . And you do a beautiful, nice precast plank with beautiful everything. Just perfect."
A year later, at a campaign rally in Kissimmee, Florida, Trump again referenced "concrete plank."
"Precast, right? Precast. Boom. Bing. Done. Keep going," Trump said.
A feature of his campaign rallies - both as a candidate and as president - has been crowds chanting "build the wall."
After being elected president, Trump's rhetoric on the wall changed to include the possibility of see-through portions. Trump explained that border agents had advised him that they need to be able to see who is on the other side of the wall; he also claimed that transparent sections would help ensure that Americans near the border would not be hit by "large sacks of drugs" thrown over by criminals.
Earlier this month, Trump further shifted his stance, arguing in a tweet that "we are not building a Concrete Wall, we are building artistically designed steel slats."
What has changed most in recent days is that an increasing number of Trump allies have openly suggested that the White House may not be wedded to the idea of a concrete wall at all as it seeks to negotiate the end of the shutdown.
Sen. Lindsey Graham, R-S.C., one of Trump's close confidants, on Sunday said the president is seeking "a physical barrier along the border in places that make sense," asserting that "the wall has become a metaphor for border security."
"In the past, every Democrat has voted for these physical barriers," Graham told reporters outside the White House after a lunch meeting with Trump. "It can't be just about 'because Trump wants it we no longer agree with it.'"
And during a television interview Sunday, White House counselor Kellyanne Conway chided Trump critics for focusing on the word "wall."
"It is a silly, semantic argument because people who just want to say 'wall, wall, wall' want it to be a four-letter word," she said on "Fox News Sunday." "There may be a wall at some places, there may be steel slats, there may be technological enhancements."
Trump has previously chafed at the suggestion that he has changed his views on the border wall. In January 2017, Kelly drew Trump's ire by telling congressional Democrats the president had "evolved" on the wall and was not "fully informed" when he made it a campaign issue.
Trump then responded on Twitter to news reports about Kelly's remarks, writing: "The Wall is the Wall, it has never changed or evolved from the first day I conceived of it."
Some immigration hard-liners argue that the construction materials matter less than whether there are physical barriers along the border, and that Trump is unlikely to face a backlash among his base.
"There may be some risk. I don't think it's that significant," said Mark Krikorian, executive director of the Center for Immigration Studies, a think tank that supports tighter controls on immigration. "I don't think people were cheering at these rallies or going to the polls because of the specific construction material for these border barriers."
King warned of trying to conflate other border security proposals with Trump's promise of a wall.
He said that even fencing was inadequate for security needs along the border and that surveillance and other technology, as well as additional border agents, would be insufficient because ultimately, they're operated by humans.
"Walls don't have prosecutorial discretion," King said.
He argued that some of Trump's recent comments had undermined his push to secure wall funding. In his Oval Office meeting a few weeks ago with House Minority Leader Nancy Pelosi, D-Calif., and Senate Minority Leader Chuck Schumer, D-N.Y., Trump said he would take the blame for any shutdown. Then, in a Christmas Day appearance in which he blamed Democrats for the shutdown, Trump described the border barrier as "a wall or fence, whatever they'd like to call it."
"Both of those verbal statements have now been used to undermine the commitment for the wall," King said.
The White House press office did not return a request for comment to explain the administration's messaging.
In an interview with Fox News Monday, Trump said funding for a wall, without specifying what that means, needed to be part of any deal to end the shutdown.
"A lot of people are looking to get their paycheck, so I'm ready to go whenever they want," he said of Democrats. "No, we are not giving up. We have to have border security and the wall is a big part of border security. The biggest part."
Democrats have seized on the inconsistent messaging from the Trump administration.
"People around the president are trying to put a brave face on it and reverse-engineer a strategy from tweets, but that's not going to solve this shutdown," Sen. Brian Schatz, D-Hawaii, said Monday.
Pelosi has mocked Trump's shifting demands, recently claiming that the president's wall had transformed into "a beaded curtain."
The lack of a unified message from the White House also raises another problem, said Rep. Gerald Connolly, D-Va.: "Who do you negotiate with, who can agree to a deal and make it stick?"
He added: "There's no reliable individual or sets of individuals in this White House, including the president. His word is good for about five minutes. And so, it is a problem."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)