Mexican actor and director Diego Luna on Wednesday screened his film "Cesar Chavez," a biographical work about the late Hispanic union leader, at a private showing at the White House hosted by U.S. President Barack Obama.

Also attending the showing were the film's two starring actresses: America Ferrera and Rosario Dawson.

Obama could not remain for the showing, but he promised to watch it "this weekend," given that, he said, it will be "very lonely" for a few days in the White House because first lady Michelle Obama and their daughters Malia and Sasha have departed on a trip to China.

The president called Cesar Chavez an "American hero" who during the 1960s launched the fight for Latino workers' rights and founded the United Farm Workers, and he went on to say that the labor leader "organized others to widen the circle of opportunity not just for the people he knew, but for future generations."

Chavez (1927-1993) was a man who "devoted this brief time that we have on Earth to making sure that this country lived up to some of its lofty ideals," the president added.

Obama said that one of the "great lessons" of the life of the labor leader is "You don't give up the fight no matter how long it takes. No matter how long the odds, you keep going, fueled by a simple creed: si, se puede (Yes, we can)."

"We've got a lot of causes that are worth fighting for," said the president, citing his ongoing push for immigration reform, guaranteeing adequate and accessible health care for all Americans and ensuring fair wages on the principle of "equal pay for equal work."

Julie Chavez Rodriguez, the granddaughter of the late activist and a staff member at the White House, was tasked with introducing the president before he gave his remarks.

"Cesar Chavez," the second fiction feature film to be directed by Luna, will begin showing in theaters on March 28.

At the recent Berlinale film festival, the work was screened outside the competition and could also be seen for several days at the South by Southwest festival held in Austin, Texas, where it received the Audience Award.

Actor Michael Peña, whose parents were born in Mexico, plays Chavez, while Ferrera stars as his wife, Helen, and Dawson plays Dolores Huerta.

Chavez "was someone who was disgusted by injustices; the farmworkers of the period worked 16 hours a day, they didn't do anything but work, they couldn't eat or go to the bathroom," Peña told Efe during the Austin festival.

Meanwhile, Luna said that what made Chavez a great leader was that he knew how to listen: "He's a man who understood what this community needed, that that was fair, to be listened to ... He told the farmworkers that their stories were important." EFE