By Scott Malone

BOSTON (Reuters) - Massachusetts Governor Deval Patrick introduced a new series of gun laws on Wednesday that would tighten rules on sales of weapons and ammunition, in the wake of last month's deadly school shooting in neighboring Connecticut.

The move comes the day after New York state adopted one of the nation's toughest gun-control laws and as U.S. President Barack Obama prepares new proposals expected to include a new national assault-weapons ban and strengthened background checks on prospective gun buyers.

"In the wake of too many tragedies, I have filed legislation to tackle the problem of gun violence and illegal firearm possession," said Patrick, a Democrat, who also proposed a hike in funding to the state's mental health programs.

Adam Lanza killed 20 young children and six educators in the December 14 attack on an elementary school in Newtown, Connecticut, using a semiautomatic rifle. Lanza, 20, who had also killed his mother, later shot himself at the school.

The killings prompted some Americans, including officials in California, Maryland and Delaware, to call for tighter restrictions on weapons and ammunition, a move that the National Rifle Association and its supporters have strongly opposed.

The attack, and others like it, also exposed holes in the U.S. mental health system.

(Reporting By Scott Malone; Editing by Paul Thomasch)