The Justice Department will start enforcing federal immigration laws by discontinuing the funding of sanctuary cities, Attorney General Jeff Sessions said on Monday while speaking at the White House.

If carried out, this new policy will result in the loss of federal money for cities that permit residents to be illegal immigrants, as Sessions stated that the Justice Department will avoid using its $4.1 billion in grant money to fund sanctuary cities. The attorney general added that the DOJ will even “claw back” funds from jurisdictions that refuse to comply with federal immigration laws.

“The Department of Justice will require that jurisdictions seeking or applying for DOJ grants to certify compliance with [U.S. Code 1373] as a condition of receiving those awards,” Sessions said.

U.S. Code 1373 is a law stating that localities cannot prevent the federal government from enforcing the nation’s laws on immigration. The law also regulates communications between local agencies and Immigration and Customs Enforcement.

“Countless Americans would be alive today … if these policies of sanctuary cities were ended,” Sessions said.

Sessions said following this policy was simply enforcing policies put in place by the Obama White House a year ago, as the previous administration made similar threats to sanctuary cities but did not act on the threats in the way Sessions is proposing.

“I strongly urge our nation’s states and cities and counties to consider carefully the harm they are doing to our citizens by refusing to enforce our immigration laws, and to rethink these policies,” Sessions said. “When cities and states refuse to enforce immigration laws, our nation is less safe.”

“We have simply got to end this policy,” Sessions said.

The DOJ’s targeting of sanctuary cities follows a January executive order from President Donald Trump aimed at improving border security and enforcing immigration laws.

Hans von Spakovsky, an immigration law expert at The Heritage Foundation, views this sanctuary city policy as a step in the right direction.

“This is a long-needed move by the Justice Department. The federal government’s chief law enforcement agency should not be giving any funds to cities or states that are obstructing federal enforcement of our immigration laws through sanctuary policies,” von Spakovsky said.