Five Republican US senators have confronted Netflix over the streaming giant's plan to adapt a Chinese sci-fi book trilogy, expressing concern over the original author's comments about claims of forced labor in Xinjiang.

Liu Cixin's bestselling "The Three-Body Problem," which tells the story of humanity's first contact with aliens, is set to become a major Netflix series co-written by the creators of "Game of Thrones."

In a letter to content boss Ted Sarandos, the senators accused Liu of "parroting dangerous [Communist Party] propaganda" and suggested Netflix was "providing a platform to Mr Liu in producing this project."

They highlighted a New Yorker article from last year in which Liu is quoted defending mass internment in China's northwestern Xinjiang region, where activists say more than one million Uighurs and other Muslim Turkic-speaking people have been incarcerated in camps.

"Would you rather that they be hacking away at bodies at train stations and schools in terrorist attacks?" Liu told the magazine. "If anything, the government is helping their economy and trying to lift them out of poverty."

According to the senators' letter, adapting Liu's work would represent "the normalization of, or apologism for, these crimes."

"We ask Netflix to seriously reconsider the implications of providing a platform to Mr Liu in producing this project," it concluded.

Netflix did not immediately respond to a request for comment.

President Donald Trump's administration has ramped up pressure on China on a wide range of issues, imposing sanctions over policies in Xinjiang. 

With Trump's reelection bid looming closer, Republicans recently pulled Netflix into the US election fray with a separate row over French film "Cuties," accused of sexualizing little girls.

Conservative activists say the drama is a by-product of an overly liberal culture often associated with Hollywood -- and that it promotes pedophilia. 

Its director denied the charges and said the movie is a critique of the over-sexualization of young girls.

Republicans have also pointed out that Netflix chief executive Reed Hastings is a significant Democratic donor.

Liu's father joined the Communists during China's civil war, but was later sent to work in coal mines in the country's north, while the author himself is described as "no dissident" in the New Yorker profile.

The trilogy by Liu -- whose famous fans include former president Barack Obama -- imagines an alternate history in which a female Chinese astrophysicist makes contact with an alien civilization, prompting global fears of an invasion.

Netflix announced its adaptation earlier this month, with "Star Wars: The Last Jedi" director Rian Johnson serving as an executive producer, along with Brad Pitt's Plan B Entertainment company.

"Game of Thrones" duo David Benioff and D.B. Weiss will co-write the series.

In an official statement at the time, Liu said the apocalyptic series "transcends time and the confines of nations, cultures and races."