John Cho and Kal Penn, who portray the troublemaking twosome at the heart of the 2004 cult hit “Harold & Kumar Go to White Castle,” admit they were just a little jumpy about the sequel. The new film, “Harold & Kumar Escape From Guantanamo Bay” (opening April 25), in which our boys run afoul of Homeland Security and air marshals all while befriending President Bush, tosses political topicality into the original movie’s mix of sex, drugs and sliders.

“I was a little worried that we might invite trouble,” says Cho, who is seated with Penn and co-star Neil Patrick Harris in an Austin hotel the day after the film screened at the South by Southwest festival. “I thought maybe it was so controversial that we’d end up with a big, stripped-down version of the movie.”

“I think the New York Times legitimized us to an extent,” Penn adds. “I was a little cautious, but I was a lot less worried (after their story said) the issue of Guantanamo has become this pop-culture phenomenon that’s very different from what it means politically. There’s political satire in this film, but it is not a political film. It does not take a stance. It’s just meant to be fun, and I hope that’s what the audience gets out of it.”

But perhaps they protest too much. “White Castle,” which was ostensibly about a late-night search for the perfect greasy burger, was also seen as a socio-political breakthrough: It proposed the unusual by putting two Asian-American guys at the center of a Hollywood slob comedy. In fact, Cho, 35, who’s of Korean descent, and Penn, 31, who’s of Indian descent, initially had some reservations initially about that film, too.

“When a white guy hands me a script and says, `I’ve written this for you,’ you get suspicious about how they’re going to treat your race and whether it’s going to be a script that doesn’t deal with (race) or deals with it,” Cho remembers. “It started to deal with it, and I thought, `Oh, this is interesting.’ They’re dealing with it in a way that feels real to me, and it’s funny. And it’s making fun of (race), which is a part of life, rather than doing it in a Black-History-Month style.”

Penn says he loved the “White Castle” script immediately but didn’t think there was any way it would get made. “I’ve had too many friends who are filmmakers who told me stories about how their universally appealing scripts that happened to have characters that were neither white nor black who were always told by studios that if they wanted financing, you’re going to have to change the characters to white or black ... Thankfully, I was completely wrong.”

Harris thinks the younger movie-going audience, at which the “H&K” franchise is aimed, has fewer hang-ups about Asian stars than some in Hollywood might think.

“I think it speaks well for the younger generation that I don’t think they (care) about the racial makeup of the leads,” he says. “I don’t think they even think about that. It just seems like (the studio) cast two hilarious dudes.”

The producers’ gamble seemed to be a losing one, at first. “White Castle” “didn’t do well,” Penn says. “It was marketed in a very traditional way. It was marketed as an ethnic movie, and it was also marketed as a stoner movie. That immediately categorized it as something that I think it really wasn’t.”

Cho remembers that some older Asian-American viewers weren’t amused. “Some Asians interpreted Harold as a stereotypical nerd role,” he explains. “And I thought of him as an Everyman. This is a kind of cinematic paradigm ... They saw it through the prism of race, though younger people are more easily able to look past that.”

But just when it seemed like “White Castle” was going to be “H&K’s” last fast-food run, word-of-mouth after the DVD release kept the buzz alive. “People were buying it, giving it to friends,” Penn says. “It created this huge wave of folks who supported the film and the characters. That’s what allowed us to do the sequel.”