UNSPECIFIED - CIRCA 1754: Soviet leader Mikhail Gorbachev and US President Ronald Reagan signing the INF Treaty 1987 (Photo by Universal History Archive/Getty Images)
President Ronald Reagan shakes hands with Soviet leader Mikhail Gorbachev in the State Dining Room in the White House, Dec. 9, 1987. The men made television addresses in the dining room after signing a treaty to eliminate intermediate-range missiles. (AP Photo/Boris Yurchenko)
** FILE ** U.S. President Ronald Reagan, right, shakes hands with Soviet leader Mikhail Gorbachev after the two leaders signed the Intermediate Range Nuclear Forces Treaty to eliminate intermediate-range missiles during a ceremony in the White House East Room in Washington, D.C., in this Tuesday, Dec. 8, 1987 file photo. Speaking on a U.S. proposal to base a missile shield in Poland and the Czech Republic Russian missile forces chief Gen. Nikolai Solovtsov warned Monday Feb. 19, 2007 that the plan could prompt Moscow to target the former allies with its own missiles. Gen. Solovtsov said it would take only five, six years _ maybe less _ to build new, upgraded versions of Russian missiles scrapped under the INF Treaty.(AP Photo/Bob Daugherty, File)
Mkhail gorbachev and ronald reagan outside of the white house prior to their talks on december 8,1987. (Photo by: Sovfoto/UIG via Getty Images)
Soviet leader Mikhail Gorbachev smile during his news conference at the Soviet Embassy in Washington on Thursday, Dec. 11, 1987. Gorbachev on included three days of summit talks with President Reagan. (AP Photo/Barry Thumma)
President Ronald Reagan smiles as he poses for photographers after delivering a speech on television, Dec. 11, 1987. Reagan discussed his summit talks with Soviet leader Mikhail Gorbachev. (AP Photo/Doug Mills)
The six Democratic presidential candidates, from left, Massachusetts Gov. Michael Dukakis; Former Arizona Gov. Bruce Babbitt; Sen. Paul Simon of Illinois; Rep. Richard Gephardt of Missouri; Jesse Jackson; and Sen. Albert Gore Jr. of Tennessee gather on Thursday, Dec. 10, 1987 in New York before a debate. The candidates stressed their support for the Reagan Gorbachev arms control treaty and hoped to benefit from Republican discord on the issue. (AP Photo/Ron Frehm)
Soviet leader Mikhail Gorbachev points to President Ronald Reagan as they walk toward the White House entrance before lunch, Dec. 10, 1987. (AP Photo/Boris Yurchenko)
Soviet leader Mikhail Gorbachev speaks during a dinner at the Soviet Embassy in Washington, Dec. 10, 1987. Seated at the dais, from left, are Raisa Gorbachev, President Ronald Reagan, first lady Nancy Reagan and Soviet Foreign Minister Eduard Shevardnadze. Others are unidentified. (AP Photo/Boris Yurchenko)
President Ronald Reagan and Soviet leader Mikhail Gorbachev share a toast during a dinner at the Soviet Embassy in Washington, Dec. 10, 1987. (AP Photo/Ron Edmonds)
President Ronald Reagan speaks during departure ceremonies for Soviet leader Mikhail Gorbachev and his wife Raisa outside the White House, Dec. 10, 1987. First lady Nancy Reagan watches at right. Others are unidentified. (AP Photo/Boris Yurchenko)
President Ronald Reagan speaks with Soviet leader Mikhail Gorbachev as they walk towards the entrance of the White House before their luncheon meeting, Dec. 10, 1987. Gorbachev, who stopped enroute to shake hands with bystanders, arrived late for the meeting. (AP Photo/Dennis Cook)
President Ronald Reagan greets Soviet leaer Mikhail Gorbachev, followed by Vice President George Bush at the White House, Dec. 10, 1987. On his way to the White House, Gorbachev stopped in front of a restaurant and got out of his car to shake hands with onlookers. He arrived an hour and a half late for his final meeting with the president. Others are unidentified. (AP Photo/Dennis Cook)
President Ronald Reagan checks his watch while talking with Soviet leader Mikhail Gorbachev during a meeting in the White House Oval Office, Dec. 9, 1987. Reagan and Gorbachev were meeting for the third time in two days. (AP Photo/J. Scott Applewhite)
First lady Nancy Reagan tugs at Raisa Gorbachev?s arm to indicate it is time to enter the White House before their tour in Washington on Wednesday, Dec. 9, 1987. Mrs. Gorbachev was answering reporters? questions as she arrived at the White House when Mrs. Reagan interrupted. (AP Photo/Scott Stewart)
President Ronald Reagan meets with Soviet leader Mikhail Gorbachev in the Oval Office of the White House, Dec. 9, 1987. (AP Photo/Barry Thumma)
Soviet leader Mikhail Gorbachev said he and President Reagan must strive to "undo the logic of the arms race" during three planned days of summit talks in a White House address in Washington, Dec. 8, 1987. The speeches by Gorbachev and Reagan were a prelude to the first of five private talks between the superpower leaders. (AP Photo/Doug Mills)
President Ronald Reagan, second from left, meets with Vice President George Bush, left, Defense Secretary Frank Carlucci, second from right, and White House Chief of Staff Howard Baker, right, in the Cabinet Room at the White House, Dec. 7, 1987. (AP Photo/Dennis Cook)
Mikhail gorbachev meeting with ronald reagan and george bush during his visit to the usa in 1987. (Photo by: Sovfoto/UIG via Getty Images)
Former Soviet President Mikhail Gorbachev receives a standing ovation from dignitaries, students, and faculty at the Kennedy School of Government Tuesday, Dec. 4, 2007. at Harvard University in Cambridge, Mass. Gorbachev said that the United States and Russia had missed opportunities to reduce the threat of nuclear weapons as he spoke on the 20th anniversary of the Intermediate-Range Nuclear Forces Treaty that he signed with President Ronald Reagan in Dec., 1987. (AP Photo/Josh Reynolds)
Soviet leader Mikhail Gorbachev and his wife Raisa wave goodbye from the top of the stairs leading to their Aeroflat plane before departing Andrews Air Force Base outside in Washington on Thursday, Dec. 10, 1987. Gorbachev completed summit talks with President Ronald Reagan. (AP Photo/Ron Edmonds)
BACK TO SLIDE
By Jim Kuhnhenn
WASHINGTON (AP) -- In an escalation of tensions, the Obama administration accused Russia on Monday of conducting tests in violation of a 1987 nuclear missile treaty, calling the breach "a very serious matter" and going public with allegations that have simmered for some time.
The treaty confrontation comes at a highly strained time between President Barack Obama and Russian President Vladimir Putin over Russia's intervention in Ukraine and Putin's grant of asylum to National Security Agency leaker Edward Snowden.
An administration official said Obama notified Putin of the U.S. determination in a letter Monday. The finding will be included in a State Department annual report on compliance with arms control treaties that will be released Tuesday.
The U.S. says Russia tested a new ground-launched cruise missile, breaking the Intermediate-Range Nuclear Forces Treaty that President Ronald Reagan signed with Soviet leader Mikhail Gorbachev. Russian officials say they have looked into the allegations and consider the matter closed.
The Obama administration has expressed its concern over possible violations before, but this is the first time that the administration has formally accused Russia of violating the treaty. It comes in the wake of the downed Malaysian airliner in Ukraine and as the U.S. and the European Union seek to ramp up sanctions against Russia, offering the administration a convenient time to release the report which had been due to come out in April.
Two officials said the U.S. is prepared to hold high-level discussions on the issue immediately and want assurances that Russia will comply with the treaty requirements going forward. The officials spoke on the condition of anonymity because they were not authorized to discuss the sensitive issue publicly by name ahead of Tuesday's report.
The New York Times first reported the U.S. move Monday evening.
In raising the issue now, the U.S. appears to be placing increased pressure on Russia and trying to further isolate it from the international community. The European Union and the United States plan to announce new sanctions against Russia this week in the face of U.S. evidence that Russia has continued to assist separatist forces in Ukraine.
The formal finding comes in the wake of congressional pressure on the White House to confront Russia over the allegations of cheating on the treaty. The treaty banned all U.S. and Russian land-based ballistic and cruise missiles with ranges between 300 miles and 3,400 miles.
The officials said the Obama administration has informed Congress and U.S. allies of its decision to seek Russian compliance.
Indeed, Obama, who has made nuclear disarmament a key foreign policy aim, has little interest in having Russia pull out of the treaty altogether.
Obama won Senate ratification of a New START treaty, which took effect in February 2011 and requires the U.S. and Russia to reduce the number of their strategic nuclear weapons to no more than 1,550 by February 2018.
Obama last year announced that he wants to cut the number of U.S. nuclear arms by another third and that he would "seek negotiated cuts" with Russia, a goal now complicated by the accusation of a missile treaty violation.
Associated Press writer Deb Riechmann contributed to this report.