Qatar says it has decided to restore full diplomatic relations with Iran and strengthen ties with the country "in all fields", disregarding the demand of Arab nations locked in a regional dispute with Doha that it lessen ties to Tehran.
In a series of tweets directed at the move, the UAE Minister of State for Foreign Affairs Dr Anwar Gargash tweeted on Thursday saying: "Doha has escalated its troubles by announcing plans they had in mind in Yemen or Iran”.
He blamed Qatar for mismanaging the crisis and prolonging it.
"The management of the crisis caused the burning of bridges, the squandering of sovereignty and the deepening of the Qatari crisis and undermined what remained of the mediator’s chances, the wisdom that we hoped for was completely absent," he wrote.
When Qatar announced its decision on Thursday, it did not mention the diplomatic crisis that has been roiling the Gulf since June, when the UAE, Saudi Arabia, Bahrain and Egypt began a boycott against Doha, accusing it of supporting terrorism.
"Qatar announced that its ambassador to Tehran will return to resume his diplomatic duties," the foreign ministry's information office said in a short statement on its website.
"The state of Qatar expressed its aspiration to strengthen bilateral relations with the Islamic Republic of Iran in all fields."
Qatar pulled its ambassador from Iran in early 2016 after Saudi Arabia's execution of a prominent Shiite cleric sparked attacks on two Saudi diplomatic posts in Iran, a move to show solidarity with the kingdom.
The foreign ministry's information office also said Qatari foreign minister Sheikh Mohammed bin Abdulrahman Al Thani had discussed "bilateral relations and means of boosting and developing them" in a telephone call with his Iranian counterpart, Mohammad Javad Zarif.
Iran on Thursday confirmed the call.
“The phone call was made last night, and the Qatari side expressed their interest in returning their ambassador to Tehran,” Iranian foreign ministry spokesman Bahram Qassemi told the official Irna news agency.
“Their ambassador had been recalled to Doha for certain consultations, and his return to Tehran is considered a logical and positive move and decision.”
“As we have repeatedly declared, the Islamic Republic of Iran’s principled policy has always been, and will be, the development of its relations with all neighbours,” Mr Qassemi added.
"Promoting co-operation and prioritising the enhancement of all-out ties with neighbouring countries will be one of our basic or ‘super’ priorities in foreign policy during president [Hassan] Rouhani’s new term in office."
The Qatari foreign ministry did not say when the country's ambassador will return to Tehran.
Even after Qatar withdrew its ambassador from Iran in 2016, the two countries maintained their valuable commercial ties. They share a massive offshore natural gas field, called the South Pars Field by Iran and the North Field by Qatar.
Since the diplomatic dispute with the quartet of Arab nations began in June, Iran has allowed Qatar's national carrier to use its airspace and sent fresh food supplies to Doha.