The Football Association is to write to all clubs advising that players should not use the phrase "from river to sea" in social media posts.
It is often interpreted as being supportive of Palestinian nationalism.
Leicester midfielder Hamza Choudhury apologised for any offence caused after using it on X, formerly Twitter.
"If this phrase is used again by a football participant, we will seek police guidance on how we should treat it and respond," an FA statement said.
Choudhury said on Tuesday that his intention had simply been to "show compassion for the innocent people that are suffering".