The US State Department said: It is in our interest to extend the "START-3" agreement, and we will continue to hold Russia accountable for its "reckless activities," according to media sources.
Earlier, White House spokeswoman Gene Saki called for the speedy release of Americans detained in Russia, after the two countries agreed to extend the New START arms control treaty for five years.
In July, a Russian court sentenced former US Marine Trevor Reed to nine years in prison, after he was found guilty of endangering the lives of two police officers. Another former US Marine, Paul Whelan, was convicted in Russia in June of espionage and sentenced to 16 years in prison.