"Any action the United States takes can have — can draw a response," de Blasio said on the Brian Lehrer radio program. "There can be an act of retaliation and obviously, we’re [New York City], the number one [terrorist] target so we have to take it seriously."
"We have to now in this environment be concerned about a whole other strand of challenges that could come home to us," the mayor added.
The United States launched 59 Tomahawk cruise missiles at the Syrian military airfield in Ash Sha'irat near Homs late Thursday.
President Donald Trump said the strikes were a response to the chemical weapons attack carried out against Syrian civilians on Tuesday, for which the United States blames the Syrian government.