Frosty relations between the two fast-food giants McDonald's and KFC appeared to deteroriate even further, after an antagonising tweet by KFC last Wednesday (Jan 3).

The 280-character message was sent out by the official Twitter account for KFC UK and Ireland, based on a parody of US President Donald Trump's infamous "nuclear button" tweet.

KFC took aim at its rival's mascot Ronald McDonald and mocked the size of his burger, adding that its box meal is "bigger and more powerful" and even has gravy.

It also mocked the fast-food joint for being a "big shoed, red nosed regime".

The tweet was a play on Mr Trump's tweet that same day, where the US leader had boasted about his nuclear button as being "bigger and more powerful" than North Korean leader Kim Jong Un's.

Some Twitter users were amused by KFC's parody, with one responding: "Will KFC have a new option chicken burger like The Nuclear chicken or the Nuked one?"

Another tweeted: "Whoever wrote this should get a raise."

Others, however, thought the joke was in poor taste. One user criticised KFC for the "social media stunt", saying: "Trump is threatening *nuclear war* against a fellow authoritarian and you parody it... Are you serious right now?"

Several also egged on other fast-food outlets such as Wendy's and Burger King to join the Twitter feud, saying: "Gotta say, I'm curious what @Wendys fearless leader's got on her desk...."

This is the second time that KFC's tweets have taken the social media world by storm.

Last October, a user discovered that the 11 people whom KFC follow on Twitter are the five Spice Girls and six men called Herb - a reference to the 11 herbs and spices used in KFC's fried chicken recipe.

The discovery went viral and many praised KFC for its ingenuity.