The United States is accusing Russia of violating a key nuclear missile treaty.
U.S. officials say Russia tested a new ground-launched cruise missile, breaking the 1987 intermediate range nuclear forces treaty.
President Barack Obama informed Russian President Vladimir Putin in a letter Monday of the U.S.' determination that Russia broke the agreement, FOX News reported.
A Washington official said the United States is prepared to engage in "senior-level bilateral dialogue immediately" with Russia. The goal will be to assure Moscow's return to compliancy.
"The United States is committed to the viability of the I.N.F. Treaty," the official added. "We encourage Russia to return to compliance with its obligations under the treaty and to eliminate any prohibited items in a verifiable manner."
The accusation comes as tensions between Russia and the West continue to grow over the crisis in Ukraine.
The European Union and the United States plan to announce new sanctions against Russia this week in the face of evidence that Russia has continued to assist separatists forces in Ukraine.