Nick Diaz at UFC Presser: Warned Nate ... I'll Beat Conor's Ass If He Touches You

Conor McGregor and Nate Diaz hate each other more then Trump and Rubio ... and now TMZ Sports has even more video that proves how deep the hatred goes.

Check out this raw footage from the UFC 196 news conference ... which shows even more smack talk than you saw on the stage.

Not only does Conor threaten members of Nate's crew -- a member who threatens Conor right back -- but there's also a moment Nate's brother Nick gives him a very real message before the stare down.

"If [Conor] even touches you, then it's on."

Conor touched him ... it was on.