UFC's Dustin Poirier on Khabib, 'Let's F*cking Fight!'

UFC star Dustin Poirier says when it comes to Khabib Nurmagomedov there's no need for trash talk ... telling TMZ Sports, "He knows what’s up. I know what’s up. Let’s f*cking fight."

Poirier is still sporting bruises from his 5-round war with Max Holloway at UFC 236 on Saturday -- but he's already looking forward to his next challenge ... a lightweight unification fight with Khabib.

Dana White has previously told us he's targeting a Sept. fight date -- and Poirier says the timing couldn't be better.

"I think Sept. is perfect for this fight," Poirier said ... "I believe that's when [Khabib's] suspension is over. That will give me plenty of time to decompress and get back into training camp. It's perfect."

Of course, Khabib is 27-0 as a pro -- and most famously smashed Conor McGregor at UFC 229 back in October. Dustin clearly respects the guy but he's confident he can serve Khabib his first loss.

"Mixed martial arts is a crazy, crazy thing to do man. There are lots of variables and lots of ways to lose. To go [undefeated] ...That’s impressive. Of course, I'm impressed by him."

30-year-old Poirier is on a pretty impressive run in the UFC right now himself ... with huge wins over studs like Justin Gaethje, Eddie Alvarez and Anthony Pettis.

Poirier fought Conor back in 2014 and lost -- so we asked if he'd be down to run that back at some point in his career. You'll want to hear his answer.

Dustin shouted out all of his supporters who have stuck with him over the years -- and tells us why he's so happy his young daughter gets to see his UFC championship belt!!!