NEW YORK – New York Mayor Michael Bloomberg signed off on a bill earlier this week that bans the sale of tobacco products in the city to anyone under age 21, the Associated Press reports.

The law makes New York the first major city in the country to restrict tobacco sales to those 21 and over. City health officials hope the change leads to a decline in smoking rates among those 18 to 21.

City Health Commissioner Thomas Farley said the idea is to make it more inconvenient for young people to get started.

"Right now, an 18-year-old can buy for a 16-year-old," he said. Once the law takes effect in six months, Farley said that 16-year-olds would "have to find someone in college or out in the workforce." The new law does not restrict those under the age of 21 from possessing tobacco.

Tobacco companies and retailers had opposed the age increase, saying it would simply drive teenagers to the city's thriving black market.

"What are you really accomplishing? It's not like they are going to quit smoking. Why? Because there are so many other places they can buy cigarettes," said Jim Calvin, president of the New York Association of Convenience Stores. "Every 18-year-old who walks out of a convenience store is just going to go to the guy in the white van on the corner."