President Recep Tayyip Erdoğan on Monday teased Greek Prime Minister Alexis Tsipras about a tie he previously gave him as a gift, as the two leaders met in Istanbul for the World Humanitarian Summit.

Shortly after Erdoğan welcomed Tsipras, he asked him about the tie he gave to Tsipras.

"Where is the tie?" Erdoğan said, and added: "I gave it to you as a gift, remember?"

Tsipras smiled and responded by saying that he would wear it next time the two leaders meet.

In 2015, Italian Prime Minister Matteo Renzi also presented Tsipras with a tie after meeting in Rome.

The Syriza leader has reportedly pledged to go open-collar until his country's debt problem is resolved.

The two-day World Humanitarian Summit, under Turkey's chairmanship in Istanbul, brought together for the first time the most important leaders in the world to address some of the most intractable humanitarian problems and try to find solutions to global crises.