© Reuters/Jonathan Ernst
US President Donald Trump
President Donald Trump walked out of the negotiations with congressional Democrats, declaring it a "total waste of time" after they repeated their refusal to fund any sort of wall on the border with Mexico.

"Just left a meeting with Chuck and Nancy, a total waste of time," Trump tweeted, referring to Senate Minority Leader Chuck Schumer (D-New York) and Speaker of the House Nancy Pelosi (D-California). "I asked what is going to happen in 30 days if I quickly open things up, are you going to approve Border Security which includes a Wall or Steel Barrier? Nancy said, NO. I said bye-bye, nothing else works!"

After the meeting, Schumer and Pelosi denounced Trump for refusing to reopen the government, just as they had the previous evening. "Again, we saw a temper tantrum because he couldn't get his way," Schumer told reporters outside the White House on Wednesday.

Federal workers are "as disappointed as we are that Democrats are unwilling to engage in good-faith negotiations," Vice President Mike Pence told reporters after the meeting.

The US government has been partially shut down for almost 19 days, after Senate Democrats refused to back a Republican-majority House bill that would allocate $5.7 billion to building the border wall. Democrats took over the House on January 3, and have proposed bills to reopen the government, but have rejected any funding to the wall, ever, calling it "immoral."

"This is a crisis... it is a humanitarian crisis, it is a security crisis," Homeland Security Secretary Kirstjen Nielsen said. "And the reality is that walls work."

Some 800,000 federal workers will soon miss their first paycheck, and each sides has accused the other of ignoring their needs and interests.

Prior to the meeting, Trump said he would be willing to declare a national emergency if the talks with Democrats failed. Asked by ABC reporter Jonathan Karl if he would be willing to reopen the government for the sake of federal workers, Trump asked him if he would do so in his place.

"If you would do that, you should never be in this position, because you'd never get anything done," the president said.