The United States has concluded that Russia violated a landmark arms control treaty by testing a prohibited ground-launched cruise missile, according to senior American officials, a finding that was conveyed by President Obama to President Vladimir V. Putin of Russia in a letter on Monday, reports The NewYork Times.

It is the most serious allegation of an arms control treaty violation that the Obama administration has leveled against Russia and adds another dispute to a relationship already burdened by tensions over the Kremlin’s support for separatists in Ukraine and its decision to grant asylum to Edward J. Snowden, the former National Security Agency contractor.

At the heart of the issue is the 1987 treaty that bans American and Russian ground-launched ballistic or cruise missiles capable of flying 300 to 3,400 miles. That accord, which was signed by President Ronald Reagan and Mikhail S. Gorbachev, the Soviet leader, helped seal the end of the Cold War and has been regarded as a cornerstone of American-Russian arms control efforts.

Russia first began testing the cruise missiles as early as 2008, according to American officials, and the Obama administration concluded by the end of 2011 that they were a compliance concern. In May 2013, Rose Gottemoeller, the State Department’s senior arms control official, first raised the possibility of a violation with Russian officials.

The New York Times reported in January that American officials had informed the NATO allies that Russia had tested a ground-launched cruise missile, raising serious concerns about Russia’s compliance with the Intermediate-range Nuclear Forces Treaty, or I.N.F. Treaty as it is commonly called. The State Department said at the time that the issue was under review and that the Obama administration was not yet ready to formally declare it to be a treaty violation.

In recent months, however, the issue has been taken up by top-level officials, including a meeting early this month of the Principals’ Committee, a cabinet-level body that includes Mr. Obama’s national security adviser, the defense secretary, the chairman of the Joint Chiefs of Staff, the secretary of state and the director of the Central Intelligence Agency. Senior officials said the president’s most senior advisers unanimously agreed that the test was a serious violation, and the allegation will be made public soon in the State Department’s annual report on international compliance with arms control agreements.

“The United States has determined that the Russian Federation is in violation of its obligations under the I.N.F. treaty not to possess, produce or flight test a ground-launched cruise missile (GLCM) with a range capability of 500 kilometers to 5,500 kilometers or to possess or produce launchers of such missiles,” that report will say.

In his letter to Mr. Putin, delivered by the American Embassy, Mr. Obama underscored his interest in a high-level dialogue with Moscow with the aim of preserving the 1987 treaty and discussing steps the Kremlin might take to come back into compliance. Secretary of State John Kerry delivered a similar message in a Sunday phone call to Sergey V. Lavrov, the Russian foreign minister.

Because the treaty proscribes testing ground-launched cruise missiles of medium-range, the Kremlin cannot undo the violation. But administration officials do not believe the cruise missile has been deployed and say there are measures the Russians can take to ameliorate the problem.

Administration officials declined to say what such steps might be, but arms control experts say they could include a promise not to deploy the system and inspections to demonstrate that the cruise missiles and their launchers have been destroyed. Because the missiles are small and easily concealed, obtaining complete confidence that the weapons have been eliminated might be difficult.

NATO’s top commander, Gen. Philip M. Breedlove, has said that the violation requires a response if it cannot be resolved.