US aerospace company Boeing is struggling to ramp up production of its 787 Dreamliner jet after a supplier's capability to provide parts for the aircraft was hampered by US sanctions against Russia, the Wall Street Journal reported on Friday.

The report said a supplier of a temperature-regulating part for the 787 jet terminated its Russian operations and moved its production out, but the transition has made it difficult for the company to keep up with Boeing's growing demand.

This delay is reportedly not only harming Boeing's business but also airlines, who now have to reduce the number of long flights offered to customers.