Every interviewer will have biases that influence perception of candidates. That's why it's essential that there are processes for consistent interview questions, assessment rubrics, and even panel-style interviews so more than one interviewer is assessing the candidate.
Also consider being transparent about your expectations for application materials and the interview. If you are hoping to hire a diverse talent pool, there may be candidates that have never been instructed in typical norms for American "business professional" attire for interviews, for instance.
Consider identifying expectations ahead of the interview and linking to resources that explain these expectations, since they are more culturally influenced than objective standards for businesses internationally. Feel free to share The Exchange's Prepare to Apply page with candidates if you would like to reference a resource about resumes, cover letters, and interview expectations in the United States.