Hate crimes in New York City have risen by 55 per cent since this time last year, police figures show.
Crimes listed included swastikas appearing on subways and a bomb threat at the Manhattan Anti-Defamation League.
Police said they had since increased patrols at Jewish centres both on a local and national scale.
A total of 56 hate crimes were reported in the city as of 12 February this year, up from 31 over the same period last year.
Some 28 cases of anti-Semitism took place – higher than any other category of hate crime.
This is despite an overall drop in crime across the city, with more than 100 fewer shootings and 15 fewer murders than during the same period in 2015-2016.
The surge in hate crimes follows a national trend, in which police say they are fielding increasing reports and concerns.
“You can’t have a candidate for president single out groups of Americans, negatively, and not have some ramifications for that,” Mr de Blasio said, “it’s obviously connected to the election.”
He added: “We could lose lives because of this.”
When asked if he blamed President Trump “directly” for the rise in hate crimes, Mr de Blasio said: “It’s more complicated than that. It’s not linear. Do I blame Donald Trump for using hate speech during his campaign? Absolutely. He did. It’s a fact.”
Police officials confirmed that hate crimes do rise and fall in relation to high profile, national and international events, but stopped short of connecting this to any particular remark specific public figures.
Overall, crime figures continued to decline during the first month of 2017. NYPD Chief of Detective Robert Boyce said the hike in hate crimes had since “levelled off”.
Other findings from the police figures included a slight increase in the number of hate crimes linked to sexual orientation, but showed no hate crimes motivated by gender or disability had been reported in the city.