The message from the White House on immigration is becoming clear: Donald Trump won’t sign any immigration bill without billions of dollars in additional border security funding, much of which is designated for a controversial wall on the Mexico border.

The stance is essentially holding 690,000 so-called “Dreamers,” young immigrants who came to the US as children and would have qualified for protection under a bipartisan bill introduced in the Senate in 2001, hostage. Both houses of Congress are scrambling to put together an immigration bill the president will sign before the clock starts ticking to kick these residents out of the country, a deadline former US officials peg as this Friday. (Jan. 19).

This afternoon, Trump soundly rejected a proposed Senate bill that sets aside $1.7 billion for border security, telling Reuters, “It’s the opposite of what I campaigned for.” He has asked instead for $18 billion for the wall, a move that would increase the budget of the Department of Homeland Security, which oversees borders, by nearly 50% if it were granted in one year.

Given that the fate of “Dreamers” is currently tied to Trump securing those funds, it’s possible to effectively put a price tag on what happens to them. The difference between what the Congress proposal allocates and Trump wants is approximately $18 billion minus the $1.7 billion, or $16.3 billion. Spread out over the entire registered “Dreamer” population, that comes to $23,632 per person. Trump campaigned on the promise that Mexico would pay for the border wall, but the administration is seeking funding from US taxpayers instead.

Last year, Trump scrapped the Deferred Action for Childhood Arrivals (DACA) act that was introduced in 2012 and protected immigrants covered under the failed 2001 Development, Relief, and Education for Alien Minors act (DREAM) bill. Brought to the US as children, these people have often grown up in the country, and voluntarily came forward to register themselves under DACA—registration that could now could lead to their expulsion.

Deportation of nearly 700,000 people, many of them pursuing higher education or working in industries like technology and health care, would squander the roughly $155 billion that US taxpayers have already invested in them, according to an earlier Quartz estimate. Over 100 CEOs from the largest US companies, including General Motors and Apple, urged Congress to get a deal done last week in an open letter.

“This is a crisis and we don’t have the luxury of a two year debate on this issue,” said Peter Boogaard, the spokesman for FWD.US, a bipartisan tech industry-backed group supporting immigration reform. “There needs to be a narrow approach that deals with DREAMers and increases border security,” he said, and there are several bills out there already that do both. “Let’s vote and bring these bills to the floor,” he said.

Senate Majority leader Mitch McConnell said late Wednesday that he couldn’t bring a bill to a vote until he knew what Trump would support. It doesn’t seem that complicated—just add another $16 billion.