THREE Americans charged with travelling to Cambodia to have sex with children have pleaded not guilty in a US court, it has been reported.

Ronald Boyajian, 49, and Erik Peeters, 41, both from California, and Jack Sporich, 75, of Arizona, entered their pleas on Monday in US federal court. They are being held without bail, and their trials are to begin on November 10, according to The Associated Press.

The men were removed from Cambodia last month under a new international law-enforcement operation dubbed Operation Twisted Traveller, which targets American nationals who travel abroad to engage in illegal sexual activity with children.

According to court affidavits, Boyajian is suspected of molesting a 10-year-old Vietnamese girl, and Peeters is accused of sexually abusing at least three Cambodian boys. Sporich is suspected of molesting at least one underage Cambodian boy.

If convicted, the men face up to 30 years in prison for each of their victims.