Russia's ambassador to the UK didn't pass up the chance to mock America's ultimatum to Iraq to choose between US support in the fight against ISIL and turning to Russia for help: the diplomat's message that it will play into terrorists’ hands was accompanied with a snapshot from the 2008 film "Harold & Kumar Escape from Guantanamo Bay."

The head of Russian diplomatic mission to Great Britain, Ambassador Alexandr Yakovenko, was quick to poke fun at an ultimatum the Pentagon has issued Iraq.

Marine Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, said on Tuesday that he had laid out a choice when he met with Iraqi Prime Minister and Defense Minister: it would be very difficult for Washington to provide the kind of support to Iraq in case the Russians were operating there as well.

US threatens to stop helping Iraq against ISIL if Baghdad asks Russia for help. The terrorists must be rejoicing pic.twitter.com/aKDaf1ae7q — Alexander Yakovenko (@Amb_Yakovenko) 21 октября 2015

The Russian diplomat, not missing a beat, responded with a snapshot from the 2008 film "Harold & Kumar Escape from Guantanamo Bay" featuring the actor and former White House liason Kal Penn as Indian-American New Jersey resident and marijuana aficionado Kumar Patel with a fake beard, wig and turban aboard a plane, joking about being a terrorist.

The message drew attention to the ultimatum, adding that “the terrorists must be rejoicing”.

The Russian Federation ambassador to the UK tweeted this Harold & Kumar pic with seriousness. I can't stop laughing. https://t.co/ZsR041AAVJ — Kal Penn (@kalpenn) 21 октября 2015

Kal Penn, in turn, responded with a series of tweets and an image of Ivan Drago, a character from the film "Rocky IV."

In his story Kumar Patel was mistaken for a terrorist and ended up on a series of comical misadventures when he escaped from Guantanamo Bay.

Drago's character in the 1985 film was supposed to be from the Soviet Union, but instead was played by Dolph Lundgren, a Swedish actor.

Not everyone in DC understood the joke; Foreign Policy ran a story with the headline: 'Is Kal Penn a Terrorist? This Russian Diplomat Seems to Think So.' The Hill covered the story using the headline 'Russian diplomat mistakes Kal Penn for a terrorist' but changed it later on.