The Massachusetts congressional delegation is questioning a push by the Swedish government to declare American lobsters an invasive species.
Sweden wants the European Union to bar imports of live American lobsters into the 28-nation bloc, a response to the appearance of 32 American lobsters in Swedish waters.
Massachusetts' delegation has sent a letter to Secretary of State John Kerry and others saying the Swedish claim needs to be backed up with scientific evidence.
Massachusetts has the second largest lobster fishery in the country. The delegation says a ban on imports to Europe would hurt the state's economy.
The U.S. State Department has said the administration is working to ensure that U.S. lobster exports are not "unjustifiably restricted."