Actor 'can't stop laughing' as Russian ambassador tweets 'terrorist' photo

After his character, Kumar Patel, was flagged as an Islamic extremist in the 2008 movie, "Harold and Kumar Escape from Guantanamo Bay," it seems the "terrorist" tag just won't shake.

Alexander Yakovenko, the Russian Ambassador to the UK, used a still from the movie -- showing Kumar imagined as an extremist and taunting an elderly female airline passenger -- to illustrate a point about U.S. involvement in the fight against ISIS in Iraq.

"U.S. threatens to stop helping Iraq against ISIL if Baghdad asks Russia for help. The terrorists must be rejoicing," the tweet said. ISIL is another acronym for ISIS.

Penn, a former White House staffer, could barely contain his glee at the apparent faux pas.

"The Russian Federation ambassador to the UK tweeted this Harold & Kumar pic with seriousness. I can't stop laughing," he wrote, retweeting the original post from Yakovenko.

The Russians went on the defensive, arguing in an official Russian Embassy, UK tweet that it was hard to find an image of a "terrorist laughing," but that the Kumar image adequately illustrated the Ambassador's point.

Penn wasn't about to let the them have the last word, however, and, tongue in cheek, replied with the words "thank you, Mr. Ambassador," accompanied by a photo of Ivan Drago, the Russian adversary from "Rocky IV."

(CNN)