The boss of one of Boeing's biggest customers highlighted the tug-of-war between the planemaker's 2 top priorities: speed and safety

• Emirates CEO Sheikh Ahmed bin Saeed Al Maktoum criticized Boeing in a CNBC interview.
• He told the planemaker: "Get your act together."
• Boeing is balancing plane safety with keeping its customers happy over delivery times.

Boeing is facing criticism from one of its biggest customers, as the CEO of Emirates told the planemaker to "get your act together," in an interview with CNBC.

During Tuesday's interview, Sheikh Ahmed bin Saeed Al Maktoum expressed disappointment with delays to deliveries of new Boeing planes Emirates has ordered.

"We're not happy really with what's going on, we always really wanted to see this aircraft entering the fleet when it had been promised — and there is a delay, it's not only to us," he told CNBC.

"I think they have to put a lot of pressure in order to make sure that they deliver to the customer whatever they promised."

Al Maktoum told CNBC that his message for Boeing is: "Get your act together and just do it. And I think they can do it."

Boeing did not immediately respond to a request for comment sent by Business Insider.

The planemaker's reputation has faltered since a 737 Max operated by Alaska Airlines lost a door plug in midair in January. In its preliminary report, the National Transportation Safety Board said the plane — delivered just 66 days earlier — left Boeing's factory missing key bolts.

As a result, aircraft production has slowed as Boeing tries to regain customers' trust.

After announcing his resignation, Boeing CEO Dave Calhoun said the company needed to slow down production in order to focus on safety and avoid another incident like the blowout.

Al Maktoum's comments highlight the difficult balancing act Boeing must achieve in the coming months — ensuring that it prioritizes safety over pretty much everything else, while also keeping delays to a minimum.

With 250 planes on order, Emirates is Boeing's biggest customer for widebody jets. The Dubai-based carrier also does a lot of business with rival Airbus: on Monday, it announced the first destinations to be served by the A350 which enters service in September. It's also by far the biggest operator of the superjumbo A380.

While Al Maktoum expressed his disappointment with Boeing, he didn't go as far as to say that this would lead to canceling orders or switching to more Airbus jets. "I won't be able to say exactly what we are planning," he told CNBC.

That contrasts with United Airlines. In January, CEO Scott Kirby said delays to the 737 Max 10 mean the carrier is building an alternative plan without it. The chief financial officer then said the Airbus A321neo is being considered as an alternative.