Iran's foreign minister says Saudi Arabia has to make "a crucial choice" — either continue supporting extremists and promoting sectarian hatred or promote good neighborliness and regional stability.

Javad Zarif said in a letter to U.N. Secretary-General Ban Ki-moon obtained Friday by The Associated Press that Iran has "no desire or interest in escalation of tension in our neighborhood" and hopes Saudi Arabia will "heed the cause of reason."

The current crisis between the Mideast rivals was sparked by Saudi Arabia's execution of Sheikh Nimr al-Nimr, a prominent opposition Shiite cleric, on Jan. 2. Crowds of protesters in Iran then attacked two Saudi diplomatic posts, leading the Saudi government to sever ties with Tehran.

Zarif said that from the first days of President Hassan Rouhani's election in June 2013, both he and the president have sent public and private signals to Saudi Arabia "about our readiness to engage in dialogue and accommodation to promote regional stability and combat destabilizing extremist violence."

But Zarif accused the Saudis of trying to prevent or defeat the nuclear deal reached in July with six world powers, of producing and supporting extremists who have carried out "acts of terror" and of waging a "senseless war" in Yemen.

Zarif also accused Saudi authorities of engaging in "numerous direct and at times lethal provocations against Iran."

He said Saudi bombers hit Iranian diplomatic facilities in Yemen several times, "killing two local service personnel, injuring a number of Yemeni guards and inflicting damage to the buildings." He said the attacks occurred on April 24 and Sept. 18 last year and most recently on Thursday.

Zarif did not specify on which dates the killings and injuries took place. An Associated Press reporter who reached the Iranian Embassy in Sanaa on Thursday just after the government announcement that it had been hit saw no damage to the building.

Zarif also accused the Saudis of mistreating Iraqi pilgrims which has fueled "public outrage in Iran," and appointing preachers who have made "a routine practice of hate speech not only against Iran but against all Shiite Muslims."

He said the Saudis also engaged in economic warfare by trying to strangle Iran's economy with drastic reductions in the price of oil, the country's main export.

Despite these provocations, Zarif said Iran has refused to retaliate or even downgrade diplomatic relations with Saudi Arabia.

Regarding the recent attacks on the Saudi diplomatic missions, he said, the government "unequivocally condemned" the violence and took immediate steps to protect the buildings and diplomats, and expressed its determination to bring the perpetrators to justice and launched an investigation.

Zarif urged a de-escalation of tensions, saying, "we all need to be united in the face of continued threats posed by extremists against all of us."