Sen. Johnson: Obama Swept Putin’s Violation of Nuclear Arms Treaty Under the Rug

US: Russia tested cruise missile, violated 1987 nuclear arms treaty (Associated Press)

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.