On Thursday, Russian President Vladimir Putin signed into law a decision that is causing serious concern.
The law signifies that Russia will no longer be part of an international treaty that prohibits nations from conducting nuclear test explosions.
The treaty's first version was adopted in 1996, with the vast majority of the world's countries joining, and it was seen as a crucial step in reducing the nuclear threat.
The Russian decision to withdraw from the treaty has been met with furrowed brows across the Atlantic.
"We are deeply concerned about Russia's planned action to withdraw its ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT)," said U.S. Secretary of State Antony Blinken in a statement from the U.S. Department of State.
Both Americans and Russians signed the treaty in 1996, but unlike Russia, the United States never formally ratified the treaty.
"Russian officials claim that Russia's decision to withdraw its ratification does not mean it will resume testing, and we urge Moscow to live up to those statements," Blinken further stated.