(CNN) An Armenian-born spy whom the Kremlin says helped to thwart a Nazi plot to assassinate Winston Churchill, Franklin D. Roosevelt and Joseph Stalin in 1943 has died aged 93.

According to the Kremlin, Goar Vartanyan and her late husband, Gevork, were involved in foiling Operation Long Jump -- a Nazi plot to kill the "Big Three" while the Allied leaders were in Tehran for their first meeting during World War II.

Vartanyan died Monday and will be buried in the Troyekurovskoye Cemetery in Moscow, according to Russian state news agency Ria Novosti.

Her husband died in 2012 at the age of 87.

Dmitry Peskov, press secretary to Russian President Vladimir Putin, said in a press conference call Wednesday that the Russian leader offered his condolences.

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