New York Governor Kathy Hochul on Monday signed ten gun control bills into law, setting new limits on buying assault-style weapons and body armour, among other measures.
It comes in the wake of mass shootings in Buffalo and Texas.
The legislation, passed on Thursday by the state legislature, raises the age required to buy or possess a semi-automatic rifle from 18 to 21.
New York already requires people to be 21 to possess a handgun.
The bill was signed by the Democratic governor after 10 people were slain last month at a supermarket in the western New York city of Buffalo by an 18-year-old with a semi-automatic rifle.
Days after that massacre, another 18-year-old fatally shot 19 students and two teachers at an elementary school in Uvalde, Texas.
Another law signed by the Governor restricts the purchase of bullet resistant vests and body armor to law enforcement or related professions.