Iranian flights to the United Arab Emirates were canceled as US sanctions began affecting Tehran’s international connectivity. Iran’s civil aviation authority announced all flights by Iranian airlines to the UAE were suspended as of midnight Wednesday local time, according to the semi-official Iranian Students’ News Agency. Thursday’s schedules confirmed no flights between Dubai’s two airports and Tehran’s Imam Khomeini International Airport.

The General Civil Aviation Authority of UAE confirmed the suspensions until further notice, as reported by state-run news agency WAM. The decision followed recent US Treasury sanctions targeting Iran’s aviation industry, which put airport operators and service providers for Iranian carriers at risk of secondary sanctions. Iran’s security chief, Mohsen Rezaee, warned regional countries not to comply with US measures, stating that blocking Iranian aircraft would result in reciprocal flight restrictions.

Only Georgia and Azerbaijan had previously announced blanket bans on Iranian carriers. Iran’s Tasnim agency reported that airports in Baghdad and Oman’s Muscat would also no longer accept Iranian flights. Mahan Air had earlier suspended all Turkey and Oman flights indefinitely, citing directives from those countries.

The cancellations further restrict Iran’s overseas connections, which were already limited before the war in February led non-domestic airlines to suspend operations to the country.