NEW YORK (AP) - New York City's new warning labels for salt-laden, chain-restaurant food is headed for a court fight.

NEW YORK (AP) New York City's new warning labels for salt-laden, chain-restaurant food is headed for a court fight.

The National Restaurant Association says it filed a lawsuit in Manhattan on Thursday, two days after the first-of-its-kind rule took effect.

The rule requires chain restaurants to put a salt-shaker icon on menu items that top the recommended daily limit of 2,300 milligrams of sodium. That's about a teaspoon.

The association says the warning will confuse and mislead consumers, and oversteps the city's authority.

But the city Law Department says it's confident the city's health board has the proper authority.

New York has faced lawsuits over other healthy-eating measures it's pioneered. Courts struck down a size limit on sugary drinks but upheld a requirement for chain eateries to post calorie counts on menus.