A New York court on Monday temporarily stopped the city from issuing fines to chain restaurants that don't specifically label very salty items on their menus.
New York is the first US city to adopt salt warnings on restaurant menus for food containing more than the daily recommended limit of 2.3 grams of sodium — about a teaspoon's worth — in a bid to fight heart disease.
The rule applies to restaurants with at least 15 locations in the United States.
However, the National Restaurant Association has fought the measure, praising the court decision and calling the sodium labelling regulation "unlawful and unprecedented."
An appeals court granted the association's request to temporarily stop the city from giving $200 fines starting Tuesday to restaurants that haven't printed a salt shaker in a black triangle on the menu next to salty dishes.
The court order will remain in place until a review by a full panel of appellate judges.
The city's health department said it was "confident" courts would ultimately uphold the sodium regulation, which was passed unanimously by the city health board in September.
Sodium, which is found in high levels in processed foods, is associated with hypertension and a higher risk of heart disease and stroke when consumed in large amounts, according to the World Health Organization.
New York has for years been at the forefront of the fight against junk food in the United States.
In 2006, the city banned trans fats at restaurants, bakeries and other food outlets.
Two years later, it became the first US city to force chain restaurants to include calorie counts on menus — which will now become federal law from December 1.
Former Mayor Michael Bloomberg tried, but failed, to ban sodas larger than 16 ounces (0.5 litres).