Mayor Bill de Blasio said New York City is now "potentially facing a threat that's different and greater than anything we have faced previously."

"Over the last 20 years, this city more than any other has suffered the results of terrorism. The terrorism inflicted upon us came from non-state actors, came from very dangerous terrorist movements and individuals," de Blasio said in a press conference he held moments ago to address how the killing of Soleimani will affect New York City.

De Blasio also said that as of Thursday night, there was "a de-facto state of war between the United States of America and Iran."

"None of us knows how this will play out. It will likely take weeks and months, maybe even years before we see where this all goes. But we have never confronted in recent decades the reality of a war with a government of a large country with an international terror network at its behest. And no one has to be reminded that New York City is the number one terror target in the United States. So we have to recognize that this creates a whole series of dangerous possibilities for our city," de Blasio said.

De Blasio added that while he was happy that Soleimani is dead, he believes the US should not go to war with Iran.

The announcement from de Blasio comes after police departments in Boston and Los Angeles said they were monitoring the situation in Iran.