Washington (CNN) The rift between President Donald Trump and House Speaker Nancy Pelosi over construction of a border wall appeared to widen on Thursday as negotiators work to strike a deal ahead of a mid-month deadline .

Over the course of the morning, both sides hardened their positions. Pelosi, who had previously been reluctant to entirely rule out wall money in a final funding agreement, made her strongest comments against the wall since the government reopened last week.

Trump went on to dismiss the speaker as "just playing games," insisting even she would be "begging for a wall" if an onslaught of undocumented immigrants swarm the border.

It was a return to the barbed back-and-forth that colored the month-long standoff that ended last week when Trump agreed to reopen the government without securing the border money wall.

He gave lawmakers three weeks to reach an agreement on a long-term government funding plan that he insists must include border wall funding.

Pelosi adopted a firm stance against that demand Thursday.

"There's not going to be any wall money in the legislation," she said during a weekly news conference.

She added that other aspects of border security involving infrastructure and technology are part of the negotiations.

In an appearance in the Oval Office, Trump offered a deeply pessimistic view of the prospects of an agreement he could approve.

"I'm not waiting for this committee and I've told a lot of people I don't expect much coming out of the committee because I keep hearing words that 'We'll give you what you want but we won't give you a wall.' And the problem is, if they don't give us a wall, it doesn't work," Trump said. He was appearing with Cabinet members and executives to sign an executive order meant to spur manufacturing.

In a set of morning tweets, Trump insisted his long-promised border wall would come to fruition one way or another, blaming "political games" for delaying the inevitable.

"Lets just call them WALLS from now on and stop playing political games! A WALL is a WALL!" he tweeted.

Later, he wrote: "The Wall is getting done one way or the other!"

The messages came as Republican and Democratic negotiators begin talks on Capitol Hill over a government funding measure that Trump insists must include border wall funding.

Trump has said if they cannot come to an agreement on a bill that includes the money he demands for the wall, he'll declare a national emergency on the southern border that would allow him to secure funds without lawmakers' approval.

Pelosi criticized that approach on Thursday, saying Trump "wanted it all to himself" and "wants Congress be completely irrelevant."

But while Pelosi appeared to rule out money for a "wall" earlier in the news conference, she expressed some openness to more enhanced fencing at the end.

Rep. Hakeem Jeffries, the No. 4 Democrat in House leadership, has said this week that Democrats would be willing to fund enhanced fencing where it makes sense. Asked for thoughts on Jeffries' comments, Pelosi pointed to vehicle barriers, also known as Normandy fencing, currently stretching across hundreds of miles along the border.

"If the President wants to call that a wall, he can call it a wall. He's referencing what we already have, almost 700 miles of wall. So again it's a place where enhanced fencing, Normandy fencing would work," she said.

"Let them have that discussion," she added, referring to the committee.

Trump and his aides were continuing to make preparations for the national emergency order this week in the event negotiators on Capitol Hill fail to reach an agreement by mid-month, White House officials say.

That included a meeting on Tuesday between the President and senior advisers to go over various options for signing the order and laying out scenarios for how it would go into effect, the officials said.

Top advisers, including son-in-law Jared Kushner, continue to warn that the move will immediately be challenged in court, hoping to temper expectations with the President that wall construction will begin immediately.

Trump said in the Oval Office on Thursday that he's "not concerned" about potential legal challenges if he declares a national emergency to build a border wall.

"No, I'm not concerned. I'm not concerned," Trump said.

"I'm waiting until February 15. On February 15, the committee will come back, and if they don't have a wall, I don't even want to waste my time reading what they have, because it's a waste of time," he said.

Drafts of the national emergency order have already been circulating among White House aides and lawyers. Trump has cast doubt on lawmakers' ability to strike an agreement he could support, leading to a belief among many West Wing aides he will eventually declare the national emergency.

Over the past several days, Trump has withdrawn from public view, a break from his practice during this month's extended government shutdown of inviting reporters to watch as he met with officials and activists to build the case for a wall.

Instead, he's been taking meetings and making calls behind closed doors. He also spoke with a few print media outlets for interviews.

Trump received another extensive briefing on Wednesday on border security, officials said, though he hasn't played a direct role in the talks playing out on Capitol Hill.

Trump's absence from public view was likely to end as the week comes to a close. He had several meetings scheduled for Thursday. And he'll sit for a television interview with CBS News to air ahead of Sunday's Super Bowl.