Erdogan stood to defend Qatar on Tuesday, saying he intends to "develop" ties with the embattled Persian Gulf state hit by sanctions from Saudi Arabia and its allies.
"Let me say at the outset that we do not think the sanctions against Qatar are good," Erdogan said in a speech in Ankara, Aljazeera reported.
"Turkey will continue and will develop our ties with Qatar, as with all our friends who have supported us in the most difficult moments," he added in reference to last year's failed coup.
Turkey has close ties with Qatar but also has good relations with the other Persian Gulf States, especially Saudi Arabia.
Erdogan was careful not to criticize Riyadh, calling on the member nations of the Persian Gulf Cooperation Council to "resolve their differences through dialogue".
"Efforts to isolate Qatar ... Will not solve any problem," said Erdogan, praising Doha's "cool-headedness" and "constructive approach".
Bahrain, Egypt, Saudi Arabia and the United Arab Emirates severed diplomatic ties and transport links with Qatar on Monday, accusing it of supporting "extremism".
"Presenting Qatar as a supporter of terrorism is a serious accusation," the Turkish leader said. "I know [Qatar's leaders] well and if that had been the case, I would have been the first head of state to confront them."