HARTFORD, Conn. -- Connecticut's governor signed into law one of America's toughest restrictions on weapons and large capacity ammunition magazines, four months after having to tell parents that 20 children had been killed in a school shooting.

Also on Thursday, Maryland's already strong gun laws will become among the toughest in the U.S. after the state Senate passed a measure that will go to the governor, who proposed the legislation, for approval.

The states' moves come as President Barack Obama tries to urge support in Congress for similar federal measures, but prospects for tough national gun control laws are slim amid political pressure by gun lobby groups and gun owners. Obama has called the Connecticut shooting in December, which also killed six adults and the gunman's mother, the worst day of his presidency.

"This is a profoundly emotional day for everyone in this room," Connecticut Gov. Dannel P. Malloy said Thursday. "We have come together in a way that few places in the nation have demonstrated the ability to do."

The shooting reignited a national debate on gun control, and Obama has planned a trip to Connecticut on Monday to increase pressure on lawmakers in Washington to act.

Colorado and New York also have passed new gun control requirements in the wake of the Connecticut shooting.

Connecticut joins states including California, New York, New Jersey and Massachusetts in having the country's strongest gun control laws, said Brian Malte, director of mobilization for the Brady Campaign to Prevent Gun Violence in Washington.

The legislation adds more than 100 firearms to the state's assault weapons ban and creates what officials have called the nation's first dangerous weapon offender registry, as well as eligibility rules for buying ammunition.

In Maryland, the state Senate voted for final passage of its gun control measure, becoming the first state in nearly 20 years to require people who buy a handgun to submit fingerprints to state police. Only five other states have a similar requirement: Connecticut, Hawaii, Massachusetts, New York and New Jersey.

Gun-control advocates say the fingerprinting requirement will help keep guns away from criminals because it will make people reluctant to buy guns for people who are not allowed to have them. Opponents say the bill erodes the Second Amendment right to bear firearms and ultimately penalizes law-abiding citizens.

The measure bans 45 types of assault weapons, although people who own them now will be able to keep them.

The measure also limits gun magazines to 10 bullets and addresses firearms access for the mentally ill. People who have been involuntarily committed to a mental health facility won't be allowed to have a gun.