Russia's President Vladimir Putin attends Navy Day celebrations in Severomorsk on Sunday.(Photo: Mikhail Klimentyev, AFP/Getty Images)
           
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 Russia's grant of asylum to National Security Agency leaker Edward Snowden.