Kobe Bryant Warns USA As New World Cup Ambassador, 'Don't F*** This Up'

Kobe Bryant's just been made an ambassador for the new 2019 hoops World Cup ... and he's got a message for his home country heading into the big tourney.

"DON'T F*** THIS UP!"

No pressure ...

The FIBA World Cup is a brand new, 32-team tournament set to go down next August and September in China ... and Kobe's new role is to help promote the event globally.

Bryant kicked that off with a video Tuesday ... callin' out Brazil, Spain, Australia, France and China to show him what they got.

But, the Lakers legend made sure to let the Stars and Stripes know they better win the damn thing (Team USA's roster has yet to be picked ... but they've been warned.)

FYI ... Yao Ming was the first ambassador for the event -- and he'll help with the draw for the tournament on March 16 in Shenzhen.