Emirates President Tim Clark said he’s keeping a close eye on Boeing Co. after the US company consistently missed delivery targets with its aircraft, suggesting one of the manufacturer’s biggest customers is running out of patience waiting for planes.

Emirates Airline is a "frustrated entity" because of a lack of planes, the carrier's president said on Wednesday, adding that it would now have an 85-strong fleet of Boeing 777-9X jets if the planemaker had been able to deliver them on time.

Executives at the Middle East’s largest airline have frequently expressed their dismay over delays and uncertainty around the delivery of the Boeing 777-9X jets.