"Daesh (also known as ISIL or ISIS), al-Qaeda, YPG, PKK, DHKP-C, and FETO are all a great risk not only to our country's security but the security and stability of our region and the whole world," Erdogan said in his United Nations Day message, Anadolu Agency reported.
"No excuse or plan can legitimize terror and arming the terrorist organizations," he said. "It is high time that cooperation and solidarity should be increased [among the] UN against terrorism."
Oct. 24, 1945 was when the UN Charter came into force and is celebrated annually as United Nations Day. In 1971, the UN General Assembly recommended the day be observed by member states as a public holiday.
Erdogan reiterated his repeated call for UN reform: "Reform at the UN is needed, which cannot be delayed, neglected, or ignored."
Recalling his famous slogan "the world is bigger than five" -- a reference to the five permanent Security Council members China, France, Russia, the United Kingdom and the United States -- Erdogan asked: "As long as the current injustice at the UN Security Council is not fixed, will it be possible to establish world peace and to achieve a complete UN reform successfully?"
He said Turkey would continue to offer support for reform which he said would turn the UN into a more "fair, democratic, transparent, effective and accountable" structure.
About his country's "significant contributions" to UN efforts, Erdogan recalled how Turkey cared for more than three million Syrians fleeing war in their homeland.
Prime Minister Binali Yildirim, in his UN Day message, called for international cooperation against terrorism "which constitutes a threat to the security and peace of all humanity”.
"As the prime minister of a country which has struggled with terrorism for years, I believe that the fight against terrorism can only be achieved by international cooperation and solidarity,” Yildirim said.