Step 1: What is asked.
We need the country whose National Assembly approved, in January 2026, a bill to ban children under 15 from social media.
Step 2: The background.
Many countries now want strict rules on social media to protect the minds of young people.
Step 3: The specific move.
The French National Assembly pushed ahead with a law setting an age limit of 15 years.
Step 4: The reason.
France wanted to shield teenagers from online bullying and screen addiction.
Step 5: Remove others.
Mauritius, Russia, and Japan were not the country in this bill.
Step 6: Conclusion.
So the country is France.
Answer: France