Trump has insisted since the 2016 campaign that a physical barrier along the USA border with Mexico is the solution to what he sees as a crisis.
Trump's allies say he is simply keeping a longstanding campaign promise and they frame his focus on his base as a smart strategy, since he will need to energize those supporters for his re-election campaign.
"I may decide a national emergency, depending on what happens over the next few days", Trump said in response to questions Sunday on the White House lawn before departing for staff meetings at the presidential retreat at Camp David, Maryland.
But not all Republicans agree with Mr Trump's insistence on keeping government agencies shuttered until the border debate is resolved.
"Where is the emergency?" the Washington Democrat said on ABC's "This Week". Speaking on CNN's "State of the Union", Intelligence Committee Chairman Adam Schiff called the idea a "nonstarter". That effort is created to squeeze Senate Republicans, some of whom are growing increasingly anxious about the extended shutdown.More news: White Sox Make Formal Offer To Manny Machado
'It is an offer he made, and it'll be discussed, ' he said on NBC's 'Meet the Press.' 'What we ought to do is open up the government first'.
Several Republicans pushed the Interior Department to find money to restaff national parks amid growing concerns over upkeep and public safety.
He said he plans to call steel companies to ask them for a design for his wall. Collins and others are also up for re-election in 2020 from states including Colorado and North Carolina where views on Trump are mixed.
'The barrier or the wall can be steel instead of concrete if that helps people.
A White House official said Trump wants to make his case about the government shutdown and wall funding in advance of Thursday's border trip. Last year, he visited San Diego to look at wall prototypes.
The back-to-back events reflect a new attempt by the President to cast the deadlock over immigration as a national security crisis, a characterization that Democrats reject but which the President's aides believe will bolster support for a border wall.More news: Troy Tulowitzki agrees to one-year deal with Yankees
"We are now planning a steel barrier rather than concrete (wall)".
Trump's demand for billions for the barrier has forced a partial government shutdown that is now in its third week. Democrats returned to Washington in the new year, taking control of the US House of Representatives, and passed legislation to reopen all closed government agencies but did not include wall funding. A day earlier, he had tweeted he didn't care that "most of the workers not getting paid are Democrats".
Donald Trump, unmoved in his demand for $5.6bn to fund a wall on the border with Mexico, tweeted that Sunday's meeting had been "productive".
Senate Minority Whip Dick Durbin on Sunday warned of legal challenges if Trump tries circumventing Congress.
President Donald Trump on Monday afternoon announced he will interrupt prime-time television to address the border, as a partial government shutdown continues.
However, opponents would nearly certainly accuse him of presidential overreach and respond with court challenges. US law and and court orders make it hard to quickly deport these families or detain them for an extended period while their asylum claims are adjudicated.More news: LeBron James, Lonzo Ball lead Lakers in All-Star voting