Sanction = right or permission given by authority to do something.

• You can’t translate the book without the sanction of the author and publishers.
• We received sanction to proceed with our plans.
• The scheme was sanctioned by the court.

Sanctions (Usually plural) = penalty, punishment. (measures taken by a state to coerce another to conform to an international agreement or norms of conduct, typically in the form of restrictions on trade or official sporting participation.)

• The government of the US decided to bring economic sanctions against Pakistan for violating the disarmament agreement.
• The UK had agreed to lift the economic sanctions against Nepal.
• Impose sanctions against violating countries.
• There are International sanctions imposed on North Korea since the Korean War.