Turkey is exercising its right to self-defense as defined by the U.N. charter in its military operations against the PKK terrorist group, U.N. Secretary-General Ban Ki-moon said Wednesday.

"I know that this action taken by Turkey was done in accordance with the U.N. charter as a way of exercising self-defense," the U.N. chief told reporters in New York following a Security Council meeting on Syria.

He said he was informed Sunday during a phone call from Turkish Prime Minister Ahmet Davutoğlu about Turkey's position.Article 51 of the charter allows countries to engage in self-defense against an armed attack.

Turkey recently launched airstrikes against the Islamic State of Iraq and al-Sham (ISIS) and PKK militants in Syria and Iraq. On Friday night, Turkish jets bombed PKK camps in northern Iraq for the first time in more than two years. Turkish jets again hit PKK targets on Sunday night and on Tuesday.

The airstrikes were in response to a wave of attacks launched by ISIS and the PKK following a July 20 suicide bomb attack by a suspected ISIS supporter that killed 32 victims in Şanlıurfa.

Ban also offered condolences to the families of the victims and to the Turkish people.

"I was again very much concerned at another loss of a serviceman in Turkey by the PKK. I strongly condemn this," he added.

Turkey, the U.S. and EU consider the PKK a terrorist organization.