Emirates' Sir Tim Clark criticized the latest delays to the Boeing 777X.BRENDAN SMIALOWSKI/AFP via Getty ImagesEmirates' president criticized Boeing over further delays to the 777X jet delivery.Tim Clark said delays have been costly, and the airline will have "a serious conversation" with Boeing.Emirates has ordered 262 of the 777X, making it the biggest customer of the much-delayed jet.The president of Emirates, one of Boeing's biggest customers, has slammed the planemaker after it announced a further delay to its much-anticipated 777X jet.Because of inspection delays and ongoing strike action, "I fail to see how Boeing can make any meaningful forecasts of delivery dates," Sir Tim Clark said in a statement shared with Business Insider."Emirates has had to make significant and highly expensive amendments to our fleet programs as a result of Boeing's multiple contractual shortfalls and we will be having a serious conversation with them over the next couple of months," he added.With 262 such planes on order — nearly half the overall total — Emirates is the largest customer for the 777X.