Iranian Foreign Minister Mohammad Javad Zarif has accused Saudi Arabia of using its escalating diplomatic row with Tehran to derail peace talks on the Syrian conflict.
"Saudi Arabia's approach is to create tension intended to negatively affect the Syrian crisis," Zarif said in a statement.
He said his country would "not allow Saudi actions to have a negative impact."
The statement coincided with an official visit to Tehran by Staffan de Mistura, the United Nations' peace envoy on Syria.
Saudi Arabia last week cut diplomatic ties with Iran in a bitter row sparked by the Sunni kingdom's execution of a prominent Shi'ite cleric.
The UN Security Council has unanimously agreed a resolution endorsing an international road map for peace in Syria, in a rare show of unity.
But there are now concerns that the dispute between Saudi Arabia and Iran, which both took part in the talks, could damage the peace process.
Zarif's remarks came one day after the six foreign ministers of the Gulf Cooperation Council (GCC) held an extraordinary meeting in Riyadh on January 9 to discuss growing tensions between Saudi Arabia and predominantly Shi'ite Iran.
The GCC groups Bahrain, Kuwait, the United Arab Emirates (U.A.E.), Qatar, Oman, and Saudi Arabia.
Its members expressed support for Saudi Arabia in its diplomatic row with Iran, condemning what they described as Iranian interference in Riyadh's internal affairs.
In a statement, the six countries "strongly denounced" the sacking of the Saudi diplomatic missions in Tehran by demonstrators angered over its execution of the Shi'ite cleric, Nimr al-Nimr.
They stated that Tehran "carries the responsibility for these terrorist acts."
Saudi Arabia also accused Iran of sponsoring terrorism and warned that the kingdom was considering new steps against Tehran.
Saudi Arabia executed Nimr on January 2 for terrorism, triggering outrage among Shi'a across the Middle East and elsewhere.
Nimr, a highly respected cleric in Saudi Arabia's Shi'ite community, was behind demonstrations calling for better treatment of the minority.
Iranian officials fiercely criticized the kingdom's authorities for the execution, and an Iranian mob stormed the Saudi Embassy and consulate in Tehran in protest.
In response to the Iran incidents, Saudi Arabia and Bahrain severed diplomatic relations with Tehran. Kuwait and Qatar recalled their ambassadors, and the U.A.E. downgraded its ties. Meanwhile, Tehran cut all commercial ties with Riyadh.
Iran has blamed Saudi Arabia for the diplomatic crisis and accused the kingdom of "sectarian hate-mongering."
In a letter to UN Secretary-General Ban Ki-moon on January 8, Zarif said Riyadh must choose between promoting extremism and fostering good relations in the Middle East.