Attorney General Jeff Sessions announced Friday that the Department of Justice will no longer issue "guidance memos" that have the effect of "adopting new regulatory requirements or amending the law" outside the federal government, and said the Justice Department would initiate a review of previously issued memos.

Sessions made the announcement in a speech to the Federalist Society in Washington Friday afternoon, and said guidance documents, which President Obama's Justice Department leaned on, should be a way to “explain existing law — not to change it.”

The change takes effect immediately, Sessions said in a memo to the entire Justice Department.

“[G]uidance may not be used as a substitute for rulemaking and may not be used to impose new requirements outside the Executive Branch,” Sessions wrote in the Friday memo. “Nor should guidance create binding standards by which the department will determine compliance with existing regulatory or statutory requirements.”

In his remarks, Sessions said “simply sending a letter” to “make new rules” is unconstitutional — and that previously issued memos might soon be rescinded.

“We will review and repeal existing guidance documents that violate this common sense principle,” he said.

According to a Justice Department press release, Sessions' memo "prevents the Department of Justice from evading required rulemaking processes by using guidance memos to create de facto regulations."

One of the more recent and infamous Justice Department guidance memos from the former administration that had this type of effect was issued by Former Attorney General Loretta Lynch in May 2016 on transgender students’ access to bathrooms.

That guidance, which was rescinded by the Trump administration in February, required public schools to permit transgender students to use the bathroom and locker room facilities that corresponded with their gender identity, not their gender at birth.

Lynch had made it clear the guidance did not impose any new legal requirements, but was a means to help school districts deal with a complicated civil rights issue and comply with Title IX. Still, many argued it was effectively a new rule that schools had to follow or risk losing federal funding.

Associate Attorney General Brand, who leads the department's Regulatory Reform Task Force, will conduct the review.

“Guidance documents can be used to explain existing law,” Brand said. “But they should not be used to change the law or to impose new standards to determine compliance with the law. This Department of Justice will not use guidance documents to circumvent the rulemaking process, and we will proactively work to rescind existing guidance documents that go too far.”