U.S. President Donald Trump has threatened to pull the United States out of the 2015 pact, under which Boeing agreed to sell 80 jets to IranAir, including 15 current-generation 777 planes.
Deliveries of the jet were originally slated to begin this year, but Boeing has been able to juggle delivery schedules with other airlines, Muilenburg said on a conference call.
When asked whether a collapse of the deal would put pressure on Boeing to further cut output of the current model of the 777, which is nearing the end of its production run, Muilenburg said current plans were "not dependent" on the Iran sanctions deal.
The remarks contrast with signals given by the company in December 2016, when a senior executive told staff the Iran sale had been factored into 777 production plans, suggesting output could be cut further without deliveries to Iran, CNN reported.
Since then, 777 orders more than doubled to 60 in 2017.
(Tim Hepher and Ankit Ajmera - Reuters)