Saudi Arabia's powerful Crown Prince Mohammed bin Salman has described Turkey as part of a "triangle of evil" along with Iran and hardline Islamist groups, Egypt's Al-Shorouk newspaper reported on Wednesday.
The Saudi prince also accused Turkey of trying to reinstate the Islamic Caliphate, abolished nearly a century ago when the Ottoman Empire collapsed.
His reported comments reflect Saudi Arabia's deep suspicion of President Tayyip Erdogan, whose ruling AK Party has its roots in Islamist politics and who has allied his country with Qatar in its dispute with Saudi Arabia and some other Gulf states.
Turkey has also worked with Iran, Saudi Arabia's arch-rival in the Middle East, to try to reduce fighting in northern Syria in recent months, and Iranian and Turkish military chiefs exchanged visits last year.
Al-Shorouk quoted Prince Mohammed as saying "the contemporary triangle of evil comprises Iran, Turkey and extremist religious groups."
The prince spoke to Egyptian newspaper editors during a visit to Cairo, on his first foreign trip since becoming heir to the oil-exporting giant last year.
He said the dispute with Qatar could be long-lasting, comparing it to the US embargo of Cuba imposed 60 years ago, but played down its impact, dismissing the Gulf emirate as "smaller than a Cairo street".
Saudi Arabia, the UAE, Egypt and Bahrain cut diplomatic and trade links with Qatar last June, suspending air and shipping routes with the world's biggest exporter of liquefied natural gas, which is home to the region's biggest US military base.
However, the Crown Prince said Qatar would not be barred from attending an Arab summit hosted by Saudi Arabia later this month.