"We did this through diplomacy", he said during an election rally in the northern province of Ordu.
In a tweet, the Turkish Armed Forces said the patrols were being carried out between Manbij and Turkey's Operation Euphrates Shield area.
"Syria strongly condemns and absolutely rejects the incursion of Turkish and American forces into the area of Manbij city", said a foreign ministry source, quoted by state news agency SANA. Turkey has long demanded that the USA avoid cooperation with the YPG, objecting YPG presence west of the Euphrates River, including the predominantly Arab town of Manbij. "They are working with the USA to liberate Manbij from terrorist elements", Yildirim said.
Turkish soldiers began entering the outskirts of YPG-held Manbij on Monday "to provide security and assure peace in the town" as part of an agreement with the United States.
Manbij has been controlled by the YPG, the United States main ally against Daesh, since 2016.
"We aim to repel YPG [terrorists] from all areas they control and to stabilize these areas", Cavusoglu said, adding that the final goal was to leave these areas to the residents.
Turkey claims the YPG has ties to the banned Kurdistan Workers' Party (PKK), and thus considers the group "terrorists".
Turkish Foreign Minister Mevlut Cavusoglu on June 4 emphasised that if Washington decides not to sell F35s to Turkey, Ankara will look further to other countries or produce its own. Should the model prove to be a success, Turkey will push for a similar arrangement in eastern Syria.
This was followed by Operation Olive Branch, which was launched on January 20, to remove YPG/PKK and Daesh terrorists from northwestern Syria's Afrin region.