"There is a danger that this dispute could lead to war," Gabriel told the Frankfurter Allgemeine Sonntagszeitung, citing what he called a "dramatic" harshness in relations between allied and neighbouring countries in the Gulf.
Gabriel said personal talks this week with his counterparts from Saudi Arabia, Qatar and Turkey, and phone calls with the foreign ministers of Iran and Kuwait underscored his concerns.
"After my talks this week, I know how serious the situation is, but I believe there are also good chances to make progress."