Story highlights Diplomatic crisis in the Middle East has been ongoing since June 4

Saudi Arabia, the UAE, Egypt and Bahrain have sought to isolate Qatar

(CNN) Qatar will restore full diplomatic relations with Iran, it announced Thursday, in a move that will infuriate the country's Arab neighbors and could deepen the region's worst diplomatic crisis in decades.

"The state of Qatar expressed its aspirations to strengthen bilateral relations with the Islamic Republic of Iran in all fields," the Qatari Foreign Ministry said in a statement.

The countries' foreign ministers spoke on the phone Thursday and discussed "bilateral relations" as well as a "number of issues of common concern," the statement said, adding Qatar's ambassador will return to Iran to exercise "diplomatic duties."

Cutting ties with Tehran was a key demand put on Qatar by Saudi Arabia, the United Arab Emirates, Bahrain and Egypt in June in return for lifting a boycott that has roiled the Middle East.

Other demands including cutting ties to terrorist organizations, reducing Turkey's military footprint in the country, and shuttering media network Al Jazeera.