So far, there appears to be no way out of the crisis, with the Democrats, who control the lower house of Congress, insisting a wall would be both ineffective and unethical.
Senator Schumer said Mr Trump "just used the backdrop of the Oval Office to manufacture a crisis, stoke fear and divert attention from the turmoil in his administration".
In an eight-minute address on Tuesday night carried live by all the major USA television networks, Mr Trump said the federal government remained shut because of the Democrats.
U.S. President Donald Trump will make his case to Americans tonight that a wall is urgently needed to resolve what he calls a crisis at the U.S. -Mexico border, as he tries to make good on a campaign promise in a dispute that has sparked an 18-day partial government shutdown. But mostly Trump still wants his wall, which Democrats describe as immoral as well as no solution to illegal immigration. Current Democratic leaders also voted for border fencing in 2006 and 2013, a change of heart that the president has highlighted multiple times.
Though Mr Trump did not declare a national emergency on Tuesday night, analysts say he may still do so before the shutdown is resolved.
Democrats remain completely opposed to the president's proposal for a wall and arranged to respond to Trump's remarks shortly after he made them.
"Some have suggested a barrier is immoral", Mr. Trump said.
Len Saunders, an immigration lawyer based near the border in Blaine, Wash., said those border guards - many of whom are supportive of the president's border-security efforts - may soon stop showing up for work as they begin to feel the shutdown's financial impact.
"Now that the television networks have made a decision to air the President's address, which if his past statements are any indication will be full of malice and misinformation, Democrats must immediately be given equal airtime", Democrat leaders Senator Chuck Schumer and House Speaker Nancy Pelosi said in a statement last night, even as various liberal quarters demanded that Trump's speech should be subjected to a delayed telecast to enable instant fact-checking given his propensity for lies and dissembling.
But the networks also carried Democrats' response, after House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer demanded equal time, predicting that Trump's speech would be "full of malice and misinformation".
Major print publications like The New York Times and The Washington Post did live updates that included fact-checking, while The Daily Beast handed over its Twitter account to reporters who cover law enforcement and national security.
"The symbol of America should be the Statue of Liberty, not a thirty-foot wall".
TIJUANA, MEXICO - JANUARY 08: Birds sit on the U.S. -Mexico border barrier at the Pacific Ocean on January 8, 2019 in Tijuana, Mexico. -Mexican border, illegal crossings there have actually dropped dramatically in recent years.
In the past, Trump's talks to the nation have been carefully scrutinized for false information.
How much support does President Trump have?
He said Mr Trump needs to re-open government while allowing the debate over border security to continue.
According to the latest Reuters/Ipsos opinion poll, 51% of Americans believe Trump "deserves most of the blame" for the government shutdown. Such a move would likely be met with a court challenge. But he took little action to get it built during his first two years in office.