Remarks attributed to Erdogan follow ratification of treaties on deployment of troops and training of Qatari forces.
The dispute between Qatar and other Arab states could lead to war, Sigmar Gabriel, German foreign minister, has told a newspaper.
However, he says he still saw a chance to defuse the tension.
“There is a danger that this dispute could lead to war,” Gabriel told the Frankfurter Allgemeine Sonntagszeitung on Saturday.
He cited what he called a “dramatic” harshness in relations between allied and neighbouring countries in the Gulf.
“After my talks this week, I know how serious the situation is, but I believe there are also good chances to make progress.”
Also on Saturday, Sergey Lavrov, Russia’s foreign minister, called for dialogue to resolve the dispute between Qatar and its Gulf neighbours.
“We cannot be happy in a situation when the relations between our partners are worsening,” Lavrov said.
“We are in favour of resolving any disagreements through … dialogue.”
Russia is “ready to try to do everything in its power” to help resolve the crisis, he said.