Speaking to MTV, director Abrams said Pegg, who plays Scotty in the science fiction movie, wept after watching a clip on his iPhone.
"I showed Simon Pegg [footage] when we were at Comic-Con. I showed him this little trailer thing and it was my favourite thing ever.
"He literally started weeping. It was ridiculous. He was sitting there, I mean he must have been plastered. Because he was looking at my iPhone [crying]."
Abrams also confirmed that Star Trek will be "a two-hour movie", saying: "I'm sick of these two hours and forty-five minute movies. Seriously, it's like I don't have enough time to stay two hours and forty-five minutes. I'm exhausted just saying that twice. I can't stand it."
Edgar Wright, who directed Pegg in Shaun Of The Dead and Hot Fuzz, hinted on his MySpace blog that he had seen a finished version of Abrams's movie and preferred it to the Star Wars prequels.
"Yesterday I saw a film that does not get released until next summer," he wrote. "I can't say much more than that, except that it delivers all the goods sorely lacking from a certain trio of prequels. Exciting stuff."