Iranian Foreign Minister Mohammad Javad Zarif will visit Qatar on Monday, officials said, for talks on relations between Tehran and Doha that have caused tensions in the Gulf.
It will be his first visit to Doha since Saudi Arabia, Bahrain, the UAE and Egypt cut ties with Qatar in June, accusing it of backing extremism and fostering ties with their Shiite rival Iran.
Zarif is to meet Qatar's emir Tamim Bin Hamad Al-Thani and Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al-Thani.
Talks would focus on relations in the Gulf, economic cooperation and the latest developments in Syria, Iraq and Yemen.
Speaking in Paris last week, Sheikh Mohammed said moves by Qatar's rivals, including the cutting of trade and transport links, were actually pushing Doha into closer ties with Tehran.
"They accuse Qatar of being close to Iran but with their measure... they push Qatar towards Iran. They are giving Qatar like a gift to Iran," he said.
Qatar said in August it was restoring full diplomatic relations with Iran. Doha along with other Sunni Arab Gulf states had pulled its ambassador from Tehran in January 2016 following attacks on Saudi diplomatic missions in Iran, spurred by Riyadh's decision to execute a Shiite cleric in the kingdom.
Oman has traditionally had closer ties with Iran than its neighbours and has maintained relations with Qatar throughout the crisis.