مشكلة check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FOREIGN

في قواعد بيانات MySQL الأمر التالي لا يتنفذ:

ALTER TABLE users
ADD CONCURRENT FOREIGN KEY (country_id) REFERENCES countries(id);

يظهر لي الخطأ التالي:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FOREIGN