"A failure to extend New START will have lasting consequences on the United States’ ability to contain the Russian nuclear threat and properly shape US nuclear forces," the lawmakers, led by Senator Bob Menendez and Congressman Eliot Engel, said in the letter.
Late last month, Russian Ambassador to the United States Anatoly Antonov said that an extension of the New START would not be a simple procedure, because the United States and Russia must first settle some crucial matters.
READ MORE: Russia Ready to Extend New START, But Future of Treaty in Doubt — Antonov
New START went into force in 2011 and covers a 10-year period with the possibility of a five-year extension. The agreement limits the number of deployed intercontinental ballistic missiles, submarine-launched ballistic missiles, nuclear armed bombers and nuclear warheads.