ATLANTA (CBS) — Burger King is calling for a ceasefire in the “burger wars.”

The fast food chain is reaching out to McDonald’s to propose a one-time, one-place collaboration that would combine the signature sandwiches of each restaurant into something unique – The McWhopper.

READ MORE: Retired professor runs Prison Book Program, giving inmates opportunities to learn

“All the tastiest bits of your Big Mac and our Whopper, united in one delicious, peace-loving burger,” Burger King writes in an open letter that ran in newspapers Wednesday.

Burger King says it was inspired to extend the olive branch by “Peace One Day,” a group pushing for an “annual day of global unity” on Sept. 21.

READ MORE: Massachusetts gas prices now at record high $4.60 a gallon

The proposed "McWhopper" packaging (Image credit McWhopper.com)

The proposed “McWhopper” packaging (Image credit McWhopper.com)

On that day, Burger King says it would open a pop-up restaurant with McDonald’s somewhere in Atlanta to serve the McWhopper.

So far, there’s been no response from McDonald’s.

MORE NEWS: Coronavirus In Massachusetts: Today's Developments