Iranian Foreign Minister Mohammad Javad Zarif said Saudi Arabia has to choose between "supporting extremists and promoting sectarian hatred" or being a constructive player in promoting stability in the Middle East.
In an opinion article in Monday's New York Times, Zarif criticizes Saudi opposition to the nuclear deal Iran struck with world powers, as well as Saudi Arabia's military campaign in Yemen, attacks against Iranian diplomatic facilities, and the stampede at last year's hajj that killed hundreds of Iranians.
The past year has brought an increase in tensions between Iran and Saudi Arabia, two regional powers that stand on opposite sides of the conflicts in Yemen and Syria.
Saudi Arabia announced a week ago it was cutting diplomatic relations with Iran, following an attack on the Saudi embassy in Tehran by crowds angry at the Saudi execution of a prominent Shi'ite cleric.
Zarif called the killing of Sheikh Nimr al-Nimr "barbaric," and after listing a series of Saudi "provocations" against Iran said his government has never reacted by downgrading their diplomatic relations.
"We have until now responded with restraint; but unilateral prudence is not sustainable," Zarif wrote in the Times. "Iran has no desire to escalate tension in the region. We need unity to confront the threats posed by extremists."
Saudi Foreign Minister Adel al-Jubeir had similarly strong comments for Iran Sunday, saying Tehran will "face the rejection of Arab countries" if it continues to support sectarian aggression, terror and violence.
Al-Jubeir spoke at an emergency meeting of Arab League foreign ministers where they issued a joint statement condemning the attack on the Saudi diplomatic offices in Iran and Iranian meddling in Arab affairs.
Lebanon, which has a large Shi'ite population and is home to the Iranian-backed Hezbollah militant group, was the only Arab League member to not support the statement.
Arab League chief Nabil Elaraby said a committee of countries will discuss interference by Iran and how to "face this violation and end it."
Sunday's Arab League statements followed similar moves by the smaller Gulf Cooperation Council on Saturday.
The council, which includes Arab League members Saudi Arabia, Bahrain, Qatar, Oman, Kuwait and the United Arab Emirates, criticized what it described as Iranian interference in the internal affairs of Saudi Arabia and the region.
"The Ministerial Council discussed the repercussions of the attack on the Saudi embassy in Tehran and the Saudi consulate in the Iranian city of Mashhad. It strongly condemned these acts and stated that Iran carries the responsibility for these terrorist acts," said GCC Secretary General Abdullatif al-Zayani following a meeting in Riyadh of the foreign ministers.