Iran accused Saudi Arabia of "sectarian hate-mongering" and said the kingdom must choose between promoting extremism and fostering good relations in the Middle East.
In a letter to United Nations Secretary-General Ban Ki-moon on January 8, Iranian Foreign Minister Javad Zarif insisted Tehran has "no desire or interest in escalation of tension in our neighborhood" and hopes Saudi Arabia will "heed the cause of reason."
But the Saudis have been "spreading delusional hype about Iran" and engaging in "numerous direct and at times lethal provocations against Iran" after failing to derail the nuclear deal reached with world powers in July, Zarif said.
He accused the Saudis of mistreating Iraqi pilgrims, which fuels "public outrage in Iran," and appointing preachers who have made "a routine practice of hate speech not only against Iran but against all Shi'ite Muslims."
Zarif offered as evidence of Iran's preference for peace, stability and "Islamic unity" Tehran's decision not to move like Riyadh to sever diplomatic relations after the split between the two regional powers erupted over the Saudis' execution of Shi'ite cleric Nimr al-Nimr.