Recep Tayyip Erdogan became the first Turkish president to visit Greece in 65 years when he arrived on Thursday and met with the Greek prime minister and president.

He immediately affronted his hosts by raising the prospect of changes to the treaty that defines their borders. On Friday, he repeated the same comments in Thrace, in northeastern Greece, home to the country’s Muslim minority, which Turkey has long referred to as a Turkish minority.

In a conciliatory gesture to his Greek hosts, Mr. Erdogan acknowledged for the first time the tiny Pomak minority as a Muslim community separate from those of Turkish origin.

“You have been fighting for survival, and I congratulate you for this,” Mr. Erdogan said in an impromptu speech, adding that the region was “a bridge between two neighbors.”