Updated

New York City Public Advocate Bill de Blasio tells FoxNews.com that he’ll work to prevent Saudi Arabian Airlines from landing at JFK and other American airports if the carrier does not change its policy of barring Israelis from flying -- even when passengers are simply looking to transfer in Saudi Arabia to another country.

"When Saudi Airlines flies from our airports, it needs to follow our laws. Discrimination based on national origin is illegal. We're going to take steps to see Saudi Airlines' lease at JFK pulled until it respects the rights of Israeli nationals," said de Blasio, a mayoral candidate who first helped expose the airline’s practices.

Federal law says an “air carrier or foreign air carrier may not subject a person in air transportation to discrimination on the basis of race, color, national origin, religion, sex or ancestry.” Conditions of the airline's leases and agreements to operate at airports, such as JFK, could be terminated if the law is broken.

For its part, Saudi Arabian Airlines is citing lack of diplomatic relations between the Kingdom of Saudi Arabia and Israel for the airline barring Israeli passengers.

Responding to criticisms, the director general of Saudi Arabian Airlines, Khalid al-Melhem, said on Friday that the decision not to allow Israeli travelers was not discriminatory, Al Arabiya reported.

“Diplomatic relations and political exchange are basic requirements for a person to enter a country,” he said to Al Arabiya. “We cannot accept a passenger if his country does not have political relations with Saudi Arabia because it would be impossible for him to enter the country.”

"No one watching Edward Snowden's month-long stay at a Moscow airport finds Saudi Airlines' claims credible," said a de Blasio spokesperson.

The former U.S. spy agency contractor, who leaked sensitive U.S. electronic surveillance program documents to the media, is holed up at a Russian airport while seeking temporary asylum in that country. In June, Snowden was able to flee Hong Kong to Russia, even after the U.S. government revoked his passport.

First reported by the New York Post, a sting operation by de Blasio’s staff uncovered that Saudi Arabian Airlines’ online ticket service does not have an option for “Israel” when a customer is asked to choose nationality during the purchase process. When a member of de Blasio's staff called the airline -- trying to book a ticket from JFK to Mumbai, India -- identifying themselves as an Israeli passport holder, the caller was told by an agent that they would not be able to fly.