Burger King ran full-page ads in The New York Times and the Chicago Tribune asking McDonald's to come together and create the ultimate burger in the name of world peace. They proposed the "McWhopper" a hybrid of each company's signature Big Mac and Whopper that will be sold in a one day pop-up store in Atlanta the mid-way point between their headquarters.

The marketing stunt would be held on Sept. 21 with proceeds going to nonprofit company Peace One Day. Burger King set up a website listing out its proposal in a compelling video, and even suggested a recipe for the hybrid burger. Their plan would contain six ingredients from the Big Mac (cheese and special sauce) and six from the Whopper (flame-grilled patty and onions).

McDonald's however quickly turned down Burger King's offer in a Facebook post, although they did note that it was a good cause and a great idea. "We love the intention but think our two brands could do something bigger to make a difference," said Easterbrook. "We commit to raise awareness worldwide, perhaps you'll join us in a meaningful global effort? P.S. A simple phone call will do next time."