Updated at 3 p.m.: Revised to include comments from Ted Cruz

WASHINGTON — Homeland Security officials laid out the stakes in the budget brinkmanship that threatens a partial government shutdown late Friday: the $5 billion the House has approved for a border wall would be enough for about 215 miles of barrier.

Less than half of that — about 100 miles, mostly in South Texas — would be frontier that doesn't already have a fence.

The rest would go to replace older, less-effective fencing or to build secondary fencing.

President Donald Trump threatened to veto any stopgap spending measure that didn't include $5 billion for a wall. With Republicans poised to lose control of the House in two weeks, any leverage he has will quickly disappear.

"We're totally prepared for a very long shutdown. And this is our only chance that we'll ever have," Trump said at a ceremony for his signing of a criminal justice overhaul.

Sen. Ted Cruz lauded Trump for digging in, calling the demand "very reasonable."

"I commend the president for standing strong on securing the border," he said, "and I hope we don't see the Democrats play partisan politics and force us into a shutdown."

"He doesn't intend to capitulate. He's not going to," the Texas Republican told reporters at the Capitol.

Trump tried unsuccessfully to cajole Senate Majority Leader Mitch McConnell to scrap the traditional filibuster rule — using a simple majority of 51 votes to sidestep the need for 60 — to make it easier to get the wall funding approved.

President Donald Trump signed criminal justice overhaul measures in the Oval Office on December 21, 2018. At right, in beard, is Sen. Ted Cruz. Photo by Olivier Douliery/ Abaca Press (Olivier Douliery / TNS)

Support for the wall is tepid in the Senate, and at least 60 senators oppose the so-called nuclear option of changing the filibuster rule, including McConnell.

Sen. John Cornyn of Texas, the majority whip, said Trump's demand to end the filibuster reflects "a desire for immediate gratification without regard for long-term consequences."

Trump insisted that drugs are pouring over the southwest border and that human trafficking is "at all-time worst in history." Ten days earlier, in a remarkable televised White House confrontation with Senate Minority Leader Chuck Schumer and Nancy Pelosi, the incoming House speaker, Trump said he would be "proud to shut down the government for border security ... I will take the mantle. I will be the one to shut it down."

But on Friday, after the House approved $5 billion in wall funding in a party-line vote, Trump sought to shift the blame.

"It's really up to the Democrats, totally up to the Democrats, as to whether or not we have a shutdown," Trump said. Arguing that illegal immigration costs the United States $285 billion annually, he said: "The wall will pay for itself on a monthly basis. I mean, literally, every month it pays for itself. So we're talking about small amounts of money."

Cruz brushed aside Trump's embrace of any blame for a shutdown, saying his "proud" comment was predicated on Pelosi's erroneous forecast that the House wouldn't approve wall funding.

Now, Cruz said, the onus is on Schumer, and "his plan B is to draw an unreasonable line, insist we leave our border unsecured and then shut the government for as long as it takes to cause the president to capitulate."

Senior officials from the Homeland Security Department briefed journalists Friday afternoon on what the proposed $5 billion could accomplish.

Their estimate of 215 miles' worth of new and replacement fencing works out to more than $23 million a mile, on average.

That's far higher than the nearly 700 miles of barrier already in place along the 2,000-mile U.S.-Mexico border. Most of that was authorized under President George W. Bush, in the Secure Fences Act of 2006.

The Government Accountability Office issued a report in 2009 that put the initial cost per mile at $2.8 to $3.9 million. But that was in urban areas, where roads were already in place.

Some of the replacement fencing installed during the Trump administration has cost about $8 million a mile. The more remote the area, the higher the cost.

Homeland Security officials insisted that comparisons are inappropriate.

"Every mile of border is different," said one official. "It depends on the terrain" and other factors.

Since Trump took office, Congress has approved $341 million for 40 miles of replacement fencing and new gates in San Diego, New Mexico and West Texas, plus gates in the Rio Grande Valley to close gaps between existing fence. Of that, 34 miles is complete.

Earlier this year, Congress provided an additional $1.375 billion for about 84 miles of new and replacement border barrier.

That includes levee wall in the Rio Grande Valley, with construction expected to start in February, plus some new wall construction in that area of South Texas, along with replacement barrier in Arizona and California.

About $500 million in contracts have been awarded, and $500 million more could be finalized in coming weeks, officials said.

Homeland Security officials wouldn't discuss the priorities for new construction but have provided plans to Congress. Officials who spoke with reporters on Friday said the top priorities are in South Texas, segments around Laredo, Yuma, Ariz., and El Centro, Calif.

Most of the new construction would be bollard fencing — steel slats similar to the fencing already in place, though taller. Officials said that the prototypes built near San Diego provided some lessons and that certain design elements would be incorporated to improve reinforcement and fortification

When Congress authorized wall funding earlier this year, it restricted construction to designs already in use.

It's unclear how much of the $5 billion would go to land acquisition, including costs to condemn property when landowners refuse to sell.

"Eminent domain is always an option. Eminent domain is a tool in our toolbox," said one senior Homeland Security official. "People would have a very difficult time finding a more public use for property than defending the United States' borders."

Washington correspondent Matthew Adams contributed to this report.