The Vietnamese word "quốc tế" is a noun that means "international" in English. It is often used to refer to relationships, events, or organizations that involve multiple countries or are recognized on a global scale.
Quan hệ quốc tế - International relations: This phrase refers to the way countries interact with one another.
Tổ chức quốc tế - International organization: This refers to an organization that operates in multiple countries, like the United Nations.