Emirates (EK, Dubai Int'l) is now expecting the first B777-9 deliveries to slip to 2021, President Tim Clark said during a conference in Dubai.

"By the end of next year we were to have eight of them. Now it doesn’t look like we will have any," he was quoted by Reuters.

Boeing still formally plans to both conduct the first flight and deliver the first B777-9 in 2020. Besides Emirates, Lufthansa (LH, Frankfurt Int'l) and Qatar Airways (QR, Doha Hamad Int'l) are also expecting to take some of the initial units. The programme has been marred by problems with the General Electric GE9X engines, as well as by failed ground stress tests in September.

"While the company is still targeting late 2020 for first delivery of the 777X, there is significant risk to this schedule given engine challenges, which are delaying first flight until early 2020," Boeing said in July.

Clark added that he expects Boeing to conduct thorough, 13-to-16-month-long testing of the B777Xs prior to their entry into service.

With thirty-five B777-8s and 115 -9s on firm order from Boeing, Emirates is the world's largest customer for the new version of the B777. The manufacturer has so far signed contracts for 334 units with 8 disclosed airline customers and a further ten units with unidentified customer(s).

Separately, the carrier said that it was of the opinion that it was allowed to serve México City Int'l as a fifth-freedom service via Barcelona El Prat, despite a recent court order in Mexico which reportedly questioned the validity of the 2016 bilateral air services agreement between Mexico and the United Arab Emirates.

"We firmly believe that the Memorandum of Understanding is valid and the ruling of the court will be the subject of an appeal by the Government of Mexico. Pending the outcome of this appeal all our rights remain valid and in force," the airline said.

Emirates plans to launch a daily service to Mexico on December 9, 2019. Aeroméxico (AM, México City Int'l) has been protesting the route ever since Emirates first floated the idea to fly to Mexico.