The United States says it is reviewing military, economic and diplomatic options to compel Russia to return to compliance with the landmark 1987 Intermediate-Range Nuclear Forces Treaty (INF).
The State Department marked the 30th anniversary of the Cold War-era treaty, which is set to expire Friday.
State Department spokesperson Heather Nauert released a statement saying the pivotal agreement, which has been a pillar of international security, is now under threat.
"The Russian Federation has taken steps to develop, test and deploy a ground-launched cruise missile system that can fly to ranges prohibited by the INF Treaty," Nauert said. "In 2014, the United States declared the Russian federation in violation of its obligations under the INF Treaty. Despite repeated U.S. efforts to engage the Russian Federation on this issue, Russian officials have so far refused to discuss the violation in any meaningful way or refute the information provided by the United States."
She stressed the U.S. is still fully committed to the treaty, which eliminates an entire class of nuclear weapons, but said Russia needs to get back in compliance.
"The administration firmly believes, however, that the United States cannot stand still while the Russian Federation continues to develop military systems in violation of the treaty. While the United States will continue to pursue a diplomatic solution, we are now pursuing economic and military measures intended to induce the Russian Federation to return to compliance," Nauert said.
"This includes a review of military concepts and options, including options for conventional, ground-launched, intermediate-range missile systems, which would enable the United States to defend ourselves and our allies, should the Russian Federation not return to compliance," she added.
She said these actions would not violate U.S. compliance.
Russia has long denied that is violating the accord. The Russian Foreign Ministry also put out a statement Friday, saying it is prepared to hold talks with the U.S. to save the INF treaty, and would comply with its obligations as long as the U.S. does the same.
In the statement, Russia said it is willing to negotiate, but added "the language of ultimatums" and attempts to impose sanctions are unacceptable.
The Arms Control Association said the INF Treaty required the United States and the Soviet Union to "eliminate and permanently forswear" all of their nuclear and conventional ground-launched ballistic and cruise missiles with ranges of 500 to 5,500 kilometers.
The treaty marked the first time the two superpowers had agreed to reduce their nuclear arsenals, eliminate an entire category of nuclear weapons, and utilize extensive, on-site inspections for verification.
Russian state media are reporting that the last leader of the Soviet Union, Mikhail Gorbachev, has called on U.S. President Donald Trump and Russian President Vladimir Putin to personally take charge of the situation to prevent the collapse of the treaty, which he signed with then-U.S. President Ronald Reagan 30 years ago.
Gorbachev said a collapse of the treaty would have "very heavy consequences."