See The First Trailer For 'Captain America: Civil War'

"Sometimes I want to punch you in your perfect teeth."

It's Avenger vs. Avenger in the first trailer for Marvel's upcoming film, "Captain America: Civil War."

The long-simmering tensions between Iron Man and Captain America come to a boil in the trailer, unveiled Tuesday night on "Jimmy Kimmel Live."

Governments are looking for some oversight over superheroes, and Robert Downey Jr.'s Tony Stark/Iron Man is willing to play along. But Captain America/Steve Rogers (played by Chris Evans) isn't, and he's also trying to protect his old friend Bucky (Sebastian Stan), who is wanted after spending years as a brainwashed assassin.

And it's not exactly a civil disagreement:

"Sometimes I want to punch you in your perfect teeth," Stark tells Rogers in the clip.

Based on what we see in the trailer, he might get the chance to try to do it, too.

"Captain America: Civil War" opens on May 6, 2016.

Once the clip was released, Marvel also unveiled a poster for the film:

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