Leaders of conservative groups are calling on Congress and President Donald Trump to reject any legislation providing amnesty for illegal immigrants, saying that rewarding them “encourages more illegal behavior.”

Almost 100 conservative leaders signed a memo on the debate over “Dreamers” and other illegal immigrants published Feb. 2 by Conservative Action Project, a coalition of conservative nonprofits and think tanks.

The coalition’s call to respect the rule of law comes after Trump’s offer during his State of the Union address Jan. 30 to compromise with Democrats on legal status for beneficiaries of the Deferred Action for Childhood Arrivals program, called “Dreamers” by advocates.

“It is unfair to those who wait for years to come here legally and chose to become U.S. citizens by respecting the law instead of rejecting it,” the leaders said of such amnesty for illegal immigrants in the memo.

They added:

Conservatives are united in the belief that the rule of law must be enforced and respected. When it comes to illegal immigration, rewarding those who break our laws encourages more illegal behavior and flies in the face of constitutional government. Not only does this reward illegal behavior, it will incentivize further illegal behavior, and encourage trends like chain migration.

Trump in September announced the phase-out of DACA, the Obama administration program that allowed work permits and prevented deportation for about 800,000 of those brought illegally to the U.S. as children, saying Congress should resolve the issue through legislation.

Trump laid out four “pillars” of his immigration policy proposal during the State of the Union speech, the first being “a path to citizenship for 1.8 million illegal immigrants who were brought here by their parents at a young age.”

“That covers almost three times more people than the previous administration. Under our plan, those who meet education and work requirements, and show good moral character, will be able to become full citizens of the United States,” he said.

On the 2016 presidential campaign trail, Trump was a staunch opponent of any form of amnesty for DACA recipients. During one debate with Democratic nominee Hillary Clinton, he said her amnesty proposal was “very unfair” to everyone who emigrated to the U.S. legally, sounding much like the Conservative Action Project’s memo.

Trump tweeted Monday that any “deal” on DACA that doesn’t include funding for a wall on the U.S.-Mexico border would be a “total waste of time.”

Trump’s executive order winding down the Obama administration program anticipated a solution in Congress that he could sign by March 5, when it is set to expire.