McGregor vows to behead 'traitor' dos Anjos at UFC 197

Featherweight champion Conor McGregor will go up two divisions to face Nate Diaz at UFC 196 in Las Vegas on March 5. Christian Petersen/Zuffa LLC/Getty Images

The UFC officially announced Monday a previously reported lightweight title fight between champion Rafael dos Anjos and Conor McGregor on March 5 -- and McGregor has already attacked his future opponent.

The championship bout will headline UFC 197 at MGM Grand Garden Arena in Las Vegas. McGregor (19-2) is the current defending featherweight champion, a title he is not ready to relinquish. He will attempt to become only the third fighter in UFC history to win belts in multiple weight classes and the first to hold two titles simultaneously.

In a Facebook post Monday, McGregor labeled dos Anjos (25-7), a Brazilian who now lives and trains in the United States, a "traitor" and promised to behead him.

"Mr. McGregor has chosen to dedicate this demolition job to the loyal people of Brazil and all the fans around the globe who stay true to their roots and loyal to their land," read the post, which was written in third person.

"Mr. McGregor has said that Rafael is a traitor to his people and vows to behead the 'American Gringo' Rafael dos Anjos, in the name of La Brasilia!"

The matchup was first reported late last week, along with a female bantamweight title fight between Holly Holm and Miesha Tate.

The UFC declined to confirm the matchup until this week, however. McGregor, who lives in Dublin but has trained in the U.S., offered his take on the delayed announcement.

"Mr. McGregor was still busy counting the take from his last fight," the post read.

McGregor is coming off a 13-second knockout over Jose Aldo at UFC 194 on Dec. 12. The event set a promotional record for live gate at a U.S.-based event. Dos Anjos is coming off his own 66-second knockout over Donald Cerrone on Dec. 19 in Orlando.