Conor McGregor didn't waste any time to start the trash talk.

Just seconds after the UFC officially announced the fight between he and Rafael dos Anjos, McGregor took to Facebook and slammed the lightweight champion. McGregor called dos Anjos a "traitor" to the Brazilian people and vowed to "behead" him in the name of "La Brasilia."

"[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," McGregor's Facebook post said. "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!""

OFFICIAL FIGHT ANNOUNCEMENT:Conor McGregor Vs Rafael Dos Anjos for the UFC Lightweight World Championship.March 5th.... Posted by Conor McGregor on Tuesday, January 12, 2016

Dos Anjos (25-7) was born and raised in Brazil, but currently lives and trains in California. Dos Anjos trains out of Kings MMA in Huntington Beach. McGregor himself has done multiple training camps in Los Angeles and Las Vegas, but calls Dublin, Ireland home.

In the post, McGregor (19-2), the UFC featherweight champion, joked that the announcement was delayed because he was still counting his money from UFC 194.

"Mr. McGregor would like to thank the fans and the media for their patience in this decision," he wrote. "Mr. McGregor was still busy counting the take from his last fight."

Dos Anjos will defend his lightweight title against McGregor in the main event of UFC 197 on March 5 in Las Vegas, it was announced Tuesday by the UFC. McGregor won the featherweight title by knocking out longtime champion Jose Aldo in just 13 seconds last month at UFC 194.

If McGregor beats dos Anjos, he would be the first fighter to ever hold two UFC titles in separate weight classes at the same time.

Dos Anjos is coming off a 66-second TKO of Donald Cerrone in the main event of UFC on FOX 17 in December. He won the belt via dominant unanimous decision over Anthony Pettis at UFC 185 in March.