NEW YORK — Young New Yorkers will soon have to wait for their 21st birthdays before they can buy a pack of smokes after lawmakers in the nation’s most populous city voted overwhelmingly to raise the tobacco-purchasing age from 18 to 21.

The City Council’s vote Wednesday makes New York the biggest city to bar cigarette sales to 19- and 20-year-olds, and one of only a few places throughout the United States that have tried to stymie smoking among young people by raising the purchasing age. The council also approved a bill that sets a minimum $10.50-a-pack price for cigarettes and steps up law enforcement on illegal tobacco sales.

“We know that tobacco dependence can begin very soon after a young person first tries smoking so it’s critical that we stop young people from smoking before they ever start,” Mayor Michael Bloomberg said.

Bloomberg, a supporter of smoking restrictions, has 30 days to sign the bills into law. The minimum age bill will take effect 180 days after enactment.

The city’s current age limit is 18, a federal minimum that’s standard in many places. Smoking in city parks and beaches already is prohibited as it is in restaurants.

Advocates say higher age limits help prevent, or at least delay, young people from taking up a habit that remains the leading cause of preventable deaths nationwide.