Turkey's operation against Kurdish militants in Syria, launched a week ago, has been widely criticised by the international community, with the US, a NATO ally, slapping sanctions on Ankara.
"We will continue to combat all terrorist groups, including Daesh (the Islamic State group), whether or not the world agrees to support our efforts," Fahrettin Altun, communications director at the Turkish presidency, told AFP.
He said the Kurdish militants had deliberately set free Islamic State (IS) prisoners from their detention camps in northern Syria in order to frighten Western powers.
"In addition to releasing thousands of Daesh prisoners from detention centres, the group deliberately targeted civilians, including reporters, near the Turkish-Syrian border before striking a dirty deal with the Assad regime," Altun said.
The Kurdish People's Protection Units (YPG) struck a deal with Damascus over the weekend in order to win its protection against the Turkish onslaught.
The deal has led to the return of Syrian forces in the Kurdish-controlled region, including the key town of Manbij, in their most significant deployment since they started withdrawing troops from the area in 2012.
"We urge all parties to look past biased media reports and fake news to appreciate Turkey's role as a bulwark against global terror," Altun told AFP.
He dismissed claims by US Defense Secretary Mark Esper that Turkey's incursion had "resulted in the release of many dangerous ISIS detainees."
Altun said such accusations were "fake news".
"It is no secret that the careers of many US officials, military and civilian, depend on the perpetuation of the Daesh threat in Syria," he said.
"In recent days, we have seen US officials use their official powers to spread fake news about the situation in northern Syria and cover up crimes committed by the PKK's Syrian offshoot."
Ankara says the YPG is a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK), which has waged a bloody insurgency inside Turkey since 1984.
Altun said people in Turkey, where the operation has widespread support, were confused about Washington's approach.
"They question why the United States, our NATO ally, would refrain from supporting our counter-terrorism efforts," he said.
"They wonder why America offers no remedy to the refugee crisis. They try to understand why Washington opposes the creation of a safe haven for refugees in northern Syria."