The president is heading to the border Thursday and said as he left Washington that he "probably" will declare a national emergency if he can't get Congress to appropriate wall funding
"I'm not prepared to do that yet, but if I have to, I will," the president told reporters on the South Lawn of the White House.
Such a strategy could quickly inflame tensions between Trump and congressional Democrats and could lead to lengthy legal battles.
First Read is your briefing from "Meet the Press" and the NBC Political Unit on the day's most important political stories and why they matter.
A roundup of the most important political news stories of the day
NBC News obtained a photo showing results of a test on a steel wall prototype.
Economists warn that a catastrophe is in the making if the partial government closure continues for weeks or months.
Mnuchin will give the House a classified briefing Thursday, after a request from the Democratic chairs of the main House investigative panels.
Nineteen days into the government shutdown, federal agencies and government employees are feeling the impact.
The conversation over DACA picked up steam on Wednesday as the stalemate over the government shutdown and the border wall showed no signs of easing.
One HUD employee said the agency took "a shrug of the shoulders kind of approach" to protecting low-income Americans from the shutdown.
Billionaire businessman Tom Steyer announced Wednesday that he will not seek the Democratic Party's 2020 presidential nomination
President Donald Trump abruptly walked out of a closed-door meeting with congressional leaders Wednesday in the White House Situation Room.
Joe Zimmerman, a sidelined federal worker, said he considered getting a second job, but needs permission. There's no one in his department to grant it.
The speaker attacked after the president threatened to withhold federal funding from the Golden State.
"The symbol of America should be the Statue of Liberty, not a 30-foot wall," Schumer said following the president's Oval Office remarks Tuesday night.
Analysis: Now wrapped in the rhetoric of a 'humanitarian crisis,' his product still isn't selling. And he knows it.
NBC News examined the remarks of Democratic leaders after the president's speech.
Read: Nancy Pelosi and Chuck Schumer's response to Donald Trump's border speech
Read the full text of President Donald Trump's speech from the Oval Office.
"This is a humanitarian crisis, a crisis of the heart and a crisis of the soul," Trump said in his speech.
It is the president first prime-time address from the Oval Office.
NBC News is fact checking the president's speech on the border and immigration as it happens.
Strange sound heard by embassy workers who fell ill matches a Caribbean cricket study suggests, but finding doesn't solve the mystery.