About one year after a Prague address calling for a world without nuclear weapons, President Barack Obama announced Tuesday that the United States and Russia will sign a treaty that will significantly limit both countries’ use and acquisition of such devices.

The Nuclear Posture Review, which the president revealed Tuesday after weeks of anticipation, also set guidelines for when the U.S. will use or threaten to use nuclear weapons.

“For the first time, preventing nuclear proliferation and nuclear terrorism is now at the top of America’s nuclear agenda,” Obama said in a statement, just days before Russian President Dmitry Medvedev’s trip to Washington D.C. for the Nuclear Security Summit. The summit starts Apr. 12, and 47 countries are expected to attend.

“The U.S. is declaring that we will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the Nuclear Non-Proliferation Treaty and in compliance with their nuclear nonproliferation obligations,” Obama said.

Obama added that the U.S. will not conduct nuclear testing and will seek to ratify the Comprehensive Test Ban Treaty that allows and monitors nuclear tests all over the world.

However, the president noted that as long as nuclear weapons exist and countries remain out of the Nuclear Non-Proliferation Treaty, the U.S. “will maintain a safe, secure and effective arsenal that guarantees the defense of the U.S., reassures allies and partners and deters potential adversaries.”

Speaker of the House Nancy Pelosi praised the review in a statement.

“This announcement sets an example for countries across the globe,” she said. “In the age of new threats, this policy works to keep dangerous weapons out of the hands of terrorists committed to our destruction.”