[Resolved] DUPLICATE CONTENTS

Background of the issue:
I migrated a site content (pages/posts) based on traffic generation. The pages/post moved and translated are those with traffic. However, we had earlier moved some other pages with very little or no traffic and are unwilling to translate such pages. The original intent is that when you try translating such pages/posts with no traffic, it should redirect to its English version since there is no translation for them.

Symptoms:
Now those pages are showing as duplicate contents in the secondary language, which is hurting our SEO.

Questions:
How do I fix the issue of pages showing as duplicate contents in the secondary language?