Well, Mr. Kirby may deny whatever he wants, not that US State Department's claims are believed by anybody with a handful of neurons in their brain, but Jaish al-Fatah, another iteration of JAN, which is Al Qaeda, took responsibility for the murder of Russia's Ambassador to Turkey. How interesting, what a coincidence, which can not be ignored, that these guys are favorite les enfant terribles of... I don't even know where to start but let's try: Senator John Mccain, CIA, Mr. Obama, US MSM--you know, the people who continue to insist that unicorns, aka "rebels" and "moderates" exist in Syria. US has a "stellar" record of growing, grooming and using their jihadists--be it Afghanistan, Bosnia, Kosovo, Iraq, you name it, and now Syria.
I lived in the US long enough to NOT remember anything of the level of all-encompassing hatred and Russophobia which dominates US media today. From CIA's own Morell to US Generals openly calling for killing of Russians:
Should such calls be made in Russia by any person, forget about Russian officers--it is inconceivable for Russian officer to call for killing of Americans on a network TV or in press--such a person will find himself facing a book being thrown at him for inciting violence and hatred. Today, anti-Russian hysteria in the US is a new normal and now, that US-supported jihadists did their dirty deed, I was astonished not to find at Yahoo news page anything mentioning the fact of JAN (or whatever the title they are using now) taking responsibility for Ambassador's murder. Once one considers who currently formulates and runs US foreign policy, one has to only recall a very famous proverb, in its rough variant: if it looks like a shit, smells like a shit and tastes like a shit then it probably is a shit. We have to wait till 20th of January 2017 when so much needed sanity will return to the Oval Office but we must always remember: dirty deeds done dirt cheap.