"As we look to expand our network, we carefully study" economic data about new destinations, he said.
Clark said Emirates's new service to Washington, which began with an inaugural flight this week, joins New York, Houston, Dallas-Fort Worth, Los Angeles, San Francisco and Seattle on the list of the airline's U.S. destinations.
Clark also said Emirates supported efforts in Congress to block the European Union from requiring airlines to trade carbon emissions emitted from flights to European countries.
The House has passed a bill to prohibit the provision, which is intended to reduce air pollution, from being applied to U.S. airlines.
Under the rules, airlines will have to reduce their emissions from 2006 levels by 3 percent by 2013 and 5 percent by 2020. The requirements took effect on Jan. 1 despite the protests from both lawmakers and the U.S. airline industry.
Clark said Emirates agreed with its American counterparts.
"We don't like ETS and we believe there must be a better global solution," he said.
The bill to block the airline emission trading requirements has cleared a key committee in the Senate, but the measure has not yet been brought up for a vote on the floor of the chamber.