The FBI and Department of Homeland Security will be on the highest alert they have been in years this July 4 holiday, according to Rep. Peter King (R-N.Y.).

In an interview with Fox News, King told network host Megyn Kelly that local authorities in New York City, along with national security units, are "the most concerned" regarding a potential attack on the Big Apple since 9/11 . He said that the concern comes from ISIS' pledge to stage an attack during Ramadan, which falls during July 4 this year.

"If American people see something, say something," King told Kelly. "I think that's especially true for people in the Muslim community, because that's where the threat is going to come from. I'm really calling on, if they know anything at all, out of the ordinary, let the police know because we're talking about potential life and death here."

King added that authorities fear ISIS has a dirty bomb that is ready to be used.

CNN reports that Homeland Security does not have any specific, credible information on an imminent attack of any kind, but is taking extra precautions.

"There is no specific, credible intelligence to indicate any threats against celebrations over the Fourth of July weekend," an anonymous Homeland Security official told CNN. "However, we have seen repeatedly calls for violence over the past year by leadership and supporters of (ISIS) against members of the military and military installations, law enforcement, the U.S. government, and the American public. These threats are always taken seriously"

Last week, the Department of Homeland Security, the FBI and the National Counterterrorism Center issue a security bulletin to all local law enforcement agencies in the country, according to CNN:

"The bulletin doesn't warn of any known active plots. But it serves as a general warning of heightened threats. It says extremists could launch attacks tied to Independence Day or in reaction to perceived defamation of the Prophet Mohammed."

Watch the complete Fox News interview between King and Kelly below.