President Donald Trump on Tuesday invited congressional leaders to a White House briefing on border security as the partial government shutdown dragged on over funding for a border wall, with Trump tweeting, "Let's make a deal?"

Semi-automatic rifles fill a wall at a gun shop in Lynnwood, Wash. (File photo: AP)

The briefing would happen Wednesday, the day before the Democrats take control of the House, but the exact agenda wasn't immediately clear, according to a person with knowledge of the briefing who was not authorized to speak publicly about the issue and spoke to The Associated Press on condition of anonymity.

Republican leaders will be attending. Senate Majority Leader Mitch McConnell, as well as the top incoming House Republicans, Kevin McCarthy of California and Steve Scalise of Louisiana, are planning to be at the briefing, according to aides. Retiring Speaker Paul Ryan will not.

Nancy Pelosi, who is expected to take over as House speaker, was also expected to attend, but she and top Senate Democrat CWashington on Tuesday joined a handful of other states that ban anyone under 21 from buying a semi-automatic assault rifle after voters passed a sweeping firearms measure in November that has drawn a court challenge from gun-rights advocates.

The ballot initiative seeks to curb gun violence by toughening background checks for people buying assault rifles, increasing the age limit to buy those firearms and requiring the safe storage of all guns. Only the age-limit portion of the measure goes into effect on Jan. 1; the rest becomes law on July 1.

Kristen Ellingboe, a spokeswoman for the Washington Alliance for Gun Responsibility, said the initiative was one of the most comprehensive gun-violence prevention measures to pass in the United States. It specifically targeted "semi-automatic assault rifles" in response to mass shootings across the country, she said.

"We've seen that assault rifles are the weapon of choice for mass shootings, and when they're used, more people are killed and injured," Ellingboe said.

Fifty-nine percent of Washington voters approved Initiative 1639 in the Nov. 6 general election.

"We've see time and again that Washington voters want action to prevent gun violence in our state," Ellingboe said. "They showed that again by supporting 1639 by a wide margin."

Opponents have sued to block it.

"Starting today, young adults between the ages of 18 to 20 will have their rights to purchase semi-automatic rifles stripped away," said Dave Workman, a spokesman for the Bellevue, Washington-based Second Amendment Foundation.

The federal lawsuit says the measure violates the Second and 14th amendments of the Constitution as well as gun sellers' rights under the Commerce Clause. Plaintiffs in the lawsuit are firearms dealers in Spokane and Vancouver, a 19-year-old competitive shooter, a 19-year-old in the Army Reserves, a 20-year-old recreational shooter, the Second Amendment Foundation and the National Rifle Association.

Washington Attorney General Bob Ferguson said he "looks forward to representing the people of the state of Washington in court against the NRA."

"The gun lobby is trying to thwart the will of nearly 60 percent of Washingtonian voters who supported common sense gun reform in our state," he said in an email.

The full measure, when it goes into effect later this year, will expand the background check process to ensure that vetting for rifle purchases is the same as for buying pistols.

Now, people in Washington who buy long guns are run through the FBI's National Instant Criminal Background Check System, or NICS. Background checks for handgun sales are done by local law enforcement agencies that can access NICS as well as more detailed records that might expose mental health issues or harder-to-find criminal records. And you must be 21 to purchase a pistol.

"This will update Washington state law so the requirements to purchase semi-automatic assault rifle will match handguns," Ellingboe said.

In most states, including over the border in Idaho and Oregon, you must be 18 to buy an assault rifle. But Republican-dominant Florida passed a law after a school shooting to increase the age limit to 21.

Nikolas Cruz was 18 when he legally bought the assault rifle he used to kill 17 people at the Marjory Stoneman Douglas High School in Parkland, Florida, last February.

Four other states — Hawaii, Illinois, Vermont and New York — also prohibit anyone under 21 from buying all firearms.

Workman of Second Amendment Foundation says Washington's measure will take away firearms from law-abiding residents who can easily pass multiple background checks. It will impair public safety and embolden criminals while placing restrictions on people who already legally own semi-automatic rifles, Workman said.uck Schumer were awaiting more details. Pelosi said Democrats would take action to "end the Trump Shutdown" by passing legislation Thursday to reopen government.

"We are giving the Republicans the opportunity to take yes for an answer," Pelosi wrote In a letter to colleagues late Tuesday. "Senate Republicans have already supported this legislation, and if they reject it now, they will be fully complicit in chaos and destruction of the President's third shutdown of his term."

The White House invitation comes after House Democrats released their plan to re-open the government without approving money for a border wall — unveiling two bills to fund shuttered government agencies and put hundreds of thousands of federal workers back on the job. They planned to pass them as soon as the new Congress convenes Thursday.

Trump spent the weekend saying Democrats should return to Washington to negotiate, firing off Twitter taunts. He then revised his aides' comments to state that he really still wants to build a border wall.

On Tuesday morning, after tweeting a New Year's message to "EVERYONE INCLUDING THE HATERS AND THE FAKE NEWS MEDIA," Trump tweeted: "The Democrats, much as I suspected, have allocated no money for a new Wall. So imaginative! The problem is, without a Wall there can be no real Border Security."

But he seemed to shift tactics later in the day, appealing to Pelosi. "Border Security and the Wall 'thing' and Shutdown is not where Nancy Pelosi wanted to start her tenure as Speaker! Let's make a deal?" he tweeted.

Whether the Republican-led Senate, under McConnell, would consider the Democratic bills — or if Trump would sign either into law — was unclear. McConnell spokesman Donald Stewart said Senate Republicans would not take action without Trump's backing.

"It's simple: The Senate is not going to send something to the president that he won't sign," Stewart said.

Even if only symbolic, the passage of the bills in the House would put fresh pressure on the president. At the same time, administration officials said Trump was in no rush for a resolution to the impasse.

Trump believes he has public opinion on his side and, at very least, his base of supporters behind him, the officials said, speaking on the condition of anonymity because they were not authorized to speak publicly.

White House officials, including the departing chief of staff, had indicated that Trump's signature campaign pledge to build the wall would not be fulfilled as advertised. Chief of staff John Kelly told the Los Angeles Times in an interview published Sunday that Trump abandoned the notion of "a solid concrete wall early on in the administration."

The Democratic package to end the shutdown would include one bill to temporarily fund the Department of Homeland Security at current levels — with $1.3 billion for border security, far less than the $5 billion Trump has said he wants for the wall — through Feb. 8 as talks continued.

It would also include another measure to fund the departments of Agriculture, Interior, Housing and Urban Development and others closed by the partial shutdown. It would provide money through the remainder of the fiscal year, to Sept. 30.

Democrats under Pelosi were all but certain to swiftly approve the package in two separate votes Thursday. They would take place after the election of a new House speaker, a contest Pelosi was expected to win as leader of the new House majority.

The White House did not respond to multiple requests for comment on the House proposal. Republican senators left for the holidays refusing to vote on any bills until all sides, including Trump, were in agreement. The lawmakers were frustrated that Trump had dismissed their earlier legislation.

The president has not said he would veto the Democratic legislation, if the bills were to land on his desk. But a prolonged crisis could hobble House Democrats' ability to proceed with their agenda, which includes investigations of the president and oversight of his administration, including Russian interference in the 2016 election.

At least one Republican, South Carolina Sen. Lindsey Graham, encouraged Trump to use the budget impasse as an opportunity to address issues beyond the border wall. But a previous attempt to reach a compromise that addressed the status of "Dreamers" — young immigrants brought to the U.S. as children — broke down last year as a result of escalating White House demands. Graham said Trump was "open minded" about his proposal.

The partial government shutdown began Dec. 22 after Trump bowed to conservative demands that he fight to make good on his vow and secure funding for the wall before Republicans lose control of the House on Wednesday. Democrats have remained committed to blocking any funding for the wall.

With neither side engaging in substantive negotiation, the effect of the partial shutdown was set to spread and to extend into the new year.