Congressional Republicans and Democrats remain at loggerheads over how to tackle border security and a supplemental aid package for Ukraine, with just one week to go till their holiday recess.

Top negotiators Sens. Chris Murphy (D-Conn.) and James Lankford (R-Okla.) laid into each side’s position in dueling Sunday morning-show appearances.

“Right now, Republican demands are unreasonable,” Murphy told NBC’s “Meet the Press.”

“If I were a cynic, I would say that Republicans have decided to tie support for Ukraine to immigration reform because they want Ukraine aid to fail,” the Democrat said.

Murphy underscored that he is “not a cynic” and that Democrats are “still trying to resolve some pretty big differences that remain.”

Lankford fired back on CBS’ “Face the Nation,” “This started with the Biden administration saying that we need to do a national security package that has Israel, Ukraine, Taiwan and the border.

“All we’re trying to do is to say what tools are needed to be able to get this back in control so we don’t have the chaos on our southern border,” the GOPer said.

Since House Speaker Mike Johnson (R-La.) took the gavel, he has been adamant that Congress pair Ukraine aid and border security together.

With that in mind, the White House rolled out a sprawling $106 billion supplemental request including support for Ukraine, Israel, Taiwan, border security and more.

But Republicans blasted the border provisions as woefully insufficient.

Both Murphy and Lankford have been negotiating on border provisions for about a month but appear to remain far apart from each other.

Encounters with migrants at the border have skyrocketed under President Biden’s watch.

During fiscal year 2023 a record 3.2 million encounters were reported, including 309,000 in October alone, according to data from US Border Patrol.

Nearly all Republicans, including moderates such as Sen. Mitt Romney (R-Utah.), appear to be on board with linking border security and Ukraine aid.

Even some Democrats including Sen. John Fetterman (D-Penn.) have said discussions about the border are a “reasonable conversation.”

Lankford lauded the Secure the Border Act of 2023, which cleared the GOP-led House of Representatives with no Democratic support earlier this year, as a model.

“Obviously, we’re not going to get 20, 30 Democrats in the Senate, or a Democratic White House to be able to sign that. But that doesn’t mean we just sit and do nothing,” he said.

Meanwhile, a large swath of the migrants pouring across the border are seeking asylum, and Murphy vowed that Democrats will oppose any legislation to block off the border to those “legitimately” pursuing asylum.

Still, he was open to “tightening some of the rules, so that you don’t have 10,000 people arriving a day.”

Democrats are seemingly wary about ceding too much ground to Republicans out of concern that they will have less leverage in future negotiations for a permanent solution to the so-called “Dreamers” — or undocumented migrants who grew up in the US — and illegal immigrants.

Last week, Politico reported that Republicans were pitching an expulsion authority similar to the pandemic-era Title 42, which permitted border agents to immediately turn away migrants at the border — even asylum-seekers.

“No, it’s actually not accurate,” Lankford said of that report. “There are several things that I have proposed on that, some things that I haven’t.”

He did not go into much detail about what was correct and what wasn’t.

This week, the White House will likely step up involvement in the negotiations over the issues, Murphy said.

The Senate is scheduled to adjourn for a holiday break at the end of this week, raising the stakes for negotiations.

White House and military officials have warned that funding for Ukraine is running low, too.

Last week, Biden chided that GOP recalcitrance on funding would be a Christmas “gift” to Russian President Vladimir Putin.

Lankford retorted, “I’m by far no fan of Vladimir Putin, and the president knows that full well.

“This is not a Christmas present to him. If we’re going to deal with national security, we’ve got to deal with Ukraine, and we have to deal with the border.”