Outside forces may have been involved in the downing of a Russian jet over northern Syria by Turkish aircraft, President of Azerbaijan Ilham Aliyev told Sputnik.

"To our knowledge, this may not have been done without the intervention of certain forces that anxiously observed the bond between Russia and Turkey. I am giving the assessment that we have because of certain objective observations," Aliyev told Rossiya Segodnya International Information Agency’s Director General Dmitry Kiselev.

Russia's Su-24 aircraft was downed by a Turkish F-16 fighter in Syria on November 24, 2015, leading to a diplomatic crisis that lasted for over half a year.