Airlines operating at Beirut's Rafic Hariri International Airport have begun implementing measures in compliance with U.S. President Donald Trump's travel ban on refugees and nationals of seven Muslim-majority countries, airport sources said on Sunday.

The measures would include denying U.S.-bound travel for nationals from those countries - Syria, Iraq, Iran, Somalia, Sudan, Libya and Yemen - who were not U.S. green card holders, the sources said.

U.S.-bound journeys from Beirut typically involve transfers in Europe, Turkey or Gulf Arab countries.