U.S. President Barack Obama said on Monday local time that he was carving out an exception for what he called “outliers” in his nuclear strategy.

In an interview with the New York Times, Obama used the term to refer to nations such as Iran and North Korea.

He said his nuclear policy target was to eliminate much of the ambiguity that has been deliberately put into America’s nuclear policy. He also stated that he intends to substantially narrow the conditions under which the United States would use nuclear weapons.

Obama will announce the Nuclear Posture Review, a compendium of his new nuclear strategy on Tuesday local time in Washington.

The New York Times reported that the United States is explicitly committing itself for the first time ever to not use nuclear weapons against nonnuclear states that are in compliance with the Nuclear Nonproliferation Treaty. This stance also extends itself to circumstances such as a biological or chemical weapons attack or a crippling cyber attack against the United States.