WASHINGTON — US 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 US 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 US-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.

Trump, who has long railed against illegal immigration at the border, has recently seized on humanitarian concerns to argue there is a broader crisis that can only be solved with a wall. But critics say the security risks are overblown and the administration is at least partly to blame for the humanitarian situation.

Trump used emotional language, referring to Americans who were killed by people in the country illegally, saying: "I've met with dozens of families whose loved ones were stolen by illegal immigration. I've held the hands of the weeping mothers and embraced the grief-stricken fathers. So sad. So terrible."

The president often highlights such incidents, though studies over several years have found immigrants are less likely to commit crimes than people born in the United States.

Trump has been discussing the idea of declaring a national emergency to allow him to move forward with the wall without getting congressional approval for the billions he's requested. But he did not mention that Tuesday night.

The partial government shutdown reached its 18th day, making the closure the second-longest in history. Hundreds of thousands of federal workers are going without pay, and government disruptions are hitting home with everyday Americans.

Trump was nearly halfway through his 9-minute address before he ever mentioned the border wall, describing it as a request from law enforcement rather than his own longstanding political pledge. He also suggested that his proposal to build the wall from steel, rather than concrete, was a concession to Democrats, although they don't see it that way.

Trump sought to put the blame on Democrats for the standoff, saying they "will not fund border security."

In fact, House Democrats passed legislation the day they took control of the House that offered $1.3 billion for border security. And Senate Democrats have approved similar funding year after year.

Seeking to keep up pressure on Trump and the Republicans, Pelosi said the House would begin passing individual bills this week to reopen some federal agencies, starting with the Treasury Department to ensure Americans receive their tax refunds. The administration says it will act on its own to ensure the refunds.

Ahead of the speech, the White House sought to shore up GOP support on Capitol Hill, where a growing number of Republicans have been expressing unease with the extended shutdown. But GOP lawmakers were still raising concerns Tuesday, talking about disruptions in payments to farmers and troubles for home buyers trying to get government-backed mortgage loans.

Vice President Mike Pence met privately with House Republicans, urging them to "stand strong" and insisting the White House wants to negotiate, according to people familiar with the conversation.

He also told the group that Trump won't retreat. "That pickup ain't got reverse in it," he said.

AP