James "Weston" Higginbotham has been missing in Kyoto since May 29.

Days into the search for an American college student missing in Japan, investigators believe it is highly probable that the 20-year-old left his family intentionally, but police remain concerned for his safety, Kyoto Prefectural Police told ABC News.

James "Weston" Higginbotham, a junior at Auburn University in Alabama, went missing on May 29 while in Kyoto on a trip with his family, police said. His parents reported him missing after he stopped responding to their messages and his phone location was turned off.

Authorities expressed concern for his well-being because Higginbotham does not speak Japanese.

Police said investigators have interviewed the family, followed Higginbotham’s movements after he left the hotel, examined items he left behind and reviewed surveillance footage.