LOS ANGELES (Reuters) - The filmmakers of Oscar-nominated “The White Helmets” about Syria’s rescue workers said the documentary’s subjects are directly affected by U.S. President Donald Trump’s travel ban and their absence at the Oscars is a “lost opportunity.”

“The White Helmets,” nominated in the Oscars short subject documentary category, gives a glimpse of the daily lives of the Syrian Civil Defense, also known as the White Helmets, civilians who volunteer as rescue workers in the war-ravaged country.

The founder of the White Helmets, Raed Saleh, and a young Syrian rescue worker who shot scenes for the documentary are unable to attend the Feb. 26 Oscars ceremony due to Trump’s executive order that bars entry to the United States for citizens from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen for 90 days.

“We feel even more responsibility and pressure to make sure that the White Helmets’ message is shared with the world if they cannot be here to share it,” the film’s producer Joanna Natasegara told Reuters at a luncheon for Oscar nominees in Beverly Hills this week.

The documentary, available on Netflix, aims to convey the “hope, inspiration and collaboration” of the White Helmets amid the years-long civil war, Natasegara said.

The absence of the two White Helmets volunteers at the Oscars prevents them from being recognized and celebrated, director Orlando von Einsiedel said.

“In this particular moment, the voices of Syrians and people from the Middle East are so important to be heard in order to break down misunderstandings and stereotypes,” he said.

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Trump’s temporary travel ban has been a deeply divisive issue across the nation. The president defended the measure as necessary for national security, whilst critics have challenged the ban as discriminatory against Muslims.

On Tuesday, a federal appeals court heard arguments in the action and whether a federal judge was wrong to suspend the temporary travel ban.

The head of the Academy of Motion Pictures Arts and Sciences, organizers of the Oscars, noted the “empty chairs” in the room during the luncheon, adding that the United States should not put barriers in the way of artists from around the world.

Iranian director Asghar Farhadi and actress Taraneh Alidoosti, who stars in his foreign-language nominated film “The Salesman,” said last week they would boycott the Academy Awards to protest Trump’s travel restrictions.

The “White Helmets” filmmakers are already planning a scripted feature-length movie on the Syrian rescue workers, with Oscar-winning actor George Clooney developing the project.