WASHINGTON (AP) — President Donald Trump urged congressional Democrats to fund his long-promised border wall Tuesday night in a somber televised address that was heavy with dark immigration rhetoric but offered little in the way of concessions or new ideas to break the standoff that has left large swaths of the government shuttered for 18 days.

Speaking to the nation from the Oval Office for the first time, Trump argued the wall was needed to resolve a security and humanitarian "crisis," blaming illegal immigration for what he said was a scourge of drugs and violence in the U.S. and asking: "How much more American blood must we shed before Congress does its job?"

Democrats in response accused Trump appealing to "fear, not facts" and manufacturing a border crisis for political gain.

Using the formal trappings of the White House, Trump hoped to gain the upper hand in the standoff over his demand for $5.7 billion to build a wall along the U.S.-Mexico border. He plans a visit to the border Thursday as he continues to pitch what was a signature promise of his 2016 presidential campaign.

He addressed the nation as the shutdown stretched through its third week, with hundreds of thousands of federal workers going without pay and some congressional Republicans growing increasingly jittery about the spreading impact of the impasse. Trump will visit the Capitol on Wednesday to meet with Senate Republicans, and has invited Democratic and Republican congressional leaders to return to the White House to meet with him later that day.

He claimed the standoff could be resolved in "45 minutes" if Democrats would just negotiate, but previous meetings have led to no agreement.

For now, Trump sees this as winning politics. TV networks had been reticent about providing him airtime to make what some feared would be a purely political speech. And that concern was heightened by the decision Tuesday by Trump's re-election campaign to send out fundraising emails and text messages to supporters trying to raise money off the speech. Their goal: A half-million dollars in a single day.

"I just addressed the nation on Border Security. Now need you to stand with me," read one message sent out after his remarks.

In their own televised remarks, Democratic House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer accused Trump of misrepresenting the situation on the border as they urged him to reopen closed government departments and turn loose paychecks for hundreds of thousands of workers.

Negotiations on wall funding could proceed in the meantime, they said.

Schumer said 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 his dire address, Trump ticked off a string of statistics and claims to make his case that there is a crisis at the border, but a number of his statements were misleading, such as saying the new trade deal with Mexico would pay for the wall, or suggesting through gruesome examples that immigrants are more likely to commit crime.