New Jersey Sen. Cory Booker praised Massachusetts gun licensing laws on Friday, even as he lamented a recent string of shootings in Boston, and the lax gun laws in other states that help contribute to gun violence here in the state.

One of more than 20 Democratic candidates running for president, Booker was scheduled to speak in Boston on Friday, but had to cancel due to flight delays in New York and New Jersey. Booker, who instead spoke to reporters on a conference call, said he wants to implement a nationwide federal gun licensing program.

The program would require any American seeking to purchase a gun of any kind, to apply for a license — much as someone would apply for a visa or passport.

Booker pointed out that nearly 70% of guns recovered by police in Massachusetts come from out of state.

“This is why we need a national strategy, a federal group of laws,” Booker said. “If we had a comprehensive, 50-state gun safety agenda, this would end.”

Booker’s plan would also would limit the number of handguns an owner can buy each month, make it easier to trace firearms back to their owner via “microstamping” of guns, bar anyone on a terrorist watch list or convicted of domestic violence from purchasing a firearm, and set aside funds for research into the causes of gun violence and its effects on communities.