Jon Jones and Daniel Cormier proved that they don't really like each other as a brawl broke out during the UFC 178 kickoff press conference on Monday afternoon at the MGM Grand in Las Vegas.

The fight started when Cormier, who will look to win the UFC light heavyweight title on Sept. 13, shoved Jones during a staredown photo opportunity.

Jones then went after Cormier as UFC director of communications Dave Sholler tried to intervene, but to no avail. Both fighters fell into the backdrop where Jones went on top of Cormier and continuously threw punches until the two were separated.

"This is certainly not a proud moment for the UFC organization," UFC chief legal officer Kirk Hendrick said in a statement. "We expect more from our athletes, especially these two gentlemen, who are very well-trained and highly educated professionals. Their actions were clearly a violation of the UFC's code of conduct."

Hendrick also added that both Jones and Cormier could face sanction for their inappropriate behavior during the news conference.

"We are going to reserve our right to penalize both fighters after the commission has made a decision. We expect more from our athletes and we are prepared to levy sanctions to reinforce the appropriate behavior. There are going to be ramifications. Whether you're the champion, or this is your first fight in the UFC, there are going to be ramifications from the UFC for these actions," Hendrick stressed.

Nevada State Athletic Commission chairman Francisco Aguilar also said in an ESPN interview that will also conduct an investigation before making a comment about the incident, but he stressed that licensed fighters are required to show sportsmanship at all times.

After the brawl, Jones continued to throw verbal jabs into Cormier as he tweeted: "Come on DC where was your takedown defense?" and "Put some ice on that face DC, you got lots of interviews tomorrow."

Jones, who is considered as the best pound-for-pound mixed martial artist in the world today, was originally scheduled to defend his title against Alexander Gustafsson, who had to withdraw from the fight after sustaining a torn meniscus in his knee.

Watch the video of the Jones-Cormier brawl below: