Washington ( CNN ) -- The United States accused Russia on Monday of violating the 1987 Intermediate-Range Nuclear Forces Treaty , citing cruise missile tests that date to 2008 , senior State Department and White House officials said . `` This is a very serious matter which we have attempted to address with Russia for some time now , '' said a senior State Department official . Russia 's suspected violation of the treaty was first reported Monday by The New York Times . `` The 2014 Compliance Report of the treaty includes a determination that the Russian Federation is in violation of its INF Treaty obligations not to possess , produce , or flight-test a ground-launched cruise missile with a range capability of 500 to 5,500 kilometers ( 310 to 3,417 miles ) , or to possess or produce launchers of such missiles , '' a White House official said , adding that they `` have kept the Congress and our allies informed of this matter . '' The violation was for cruise missile tests that date back to 2008 , prompting an administration review as to whether the tests are in violation of the 1987 treaty between the United States and Russia banning medium range missiles . President Barack Obama has written his Russian counterpart Vladimir Putin a letter about the matter . Monday 's news comes during a increasingly icy period for relations between Washington and Moscow due to the ongoing conflict in Ukraine , where Russia is said to be supporting separatists . The United States will place new sanctions on Russia this week , White House Deputy National Security Adviser Tony Blinken announced Monday without elaborating . Opinion : We must end this trade in weapons of war . The United States also is upset with Russia for giving asylum to National Security Agency leaker Edward Snowden . The officials said the administration has also informed NATO allies of Russia 's suspected violation . The officials said Washington , which first raised the issue with Russia last year , has recently notified Moscow of the determination and has proposed senior-level talks in the effort to bring Russia back into compliance with its obligations under the treaty . Officials pointed out the treaty does n't just protect the United States and Russia , but the 11 former Soviet republics also a party to the treaty , as well as allies in Europe and East Asia . `` The United States is committed to the viability of the INF Treaty . We encourage Russia to return to compliance with its obligations under the Treaty and to eliminate any prohibited items in a verifiable manner , '' the senior state department official told CNN . One of the officials said further talks with America 's allies would `` take into account the impact of this Russian violation on our collective security if Russia does not return to compliance . '' The administration has been raising this issue with Russia for more than a year . The Russians responded that they investigated the matter and considered it closed . CNN 's Athena Jones contributed to this report .
NEW : President Obama sends Vladimir Putin letter addressing the matter . U.S. believes Russia has tested cruise missiles not allowed by 1987 treaty . Moscow says it investigated and considers the matter closed . Source tells CNN that Washington has proposed senior-level talks with Moscow .