New York City, in an effort to combat the gender pay gap, on Tuesday became the first U.S. city to ban employers from asking job applicants about previous salaries.

Asking about past salaries can perpetuate unequal pay levels rather than allow applicants to seek pay based on their qualifications and earnings potential, city officials said.

Under the city's new law, the first of its kind to take effect in the country, employers who ask applicants about previous salaries or search for the information in public records will be subject to a fine of up to $250,000.