A joint July 4 celebration that was scheduled to take place between U.S. and UK military personnel and their families at Britain’s largest U.S. air force base has been canceled, military officials announced Thursday, citing “the most current, local threat assessments.”

The threat level has increased following an ISIS leader’s call for Muslims loyal to the terror group to make sure the Islamic holy month of Ramadan is a “month of disaster” to western targets, NBC News reports.

While U.S. law enforcement has not announced a specific, immediate threat, many local agencies are beefing up security for Fourth of July festivities.

New York City will provide “enhanced counterterrorism and security measures” for its annual July 4 fireworks event, the NYPD said.

The Royal Air Force Lakenheath said on its Facebook page that they “sincerely apologize” for the cancellation of festivities and that the decision was made with “heavy hearts,” NBC News reports.

The statement added:

The decision was made due to the most current, local threat assessments. We make every effort to ensure the safety of our Airmen, their families and our U.K. partners and must make difficult decisions like this when lives are on the line. Both the main event on Saturday, July 4th, as well as the preview party scheduled for Friday, July 3rd, are cancelled. We sincerely apologize for any inconvenience this may cause, and, whether you’re celebrating the 4th of July holiday or simply enjoying the British summer, we wish you a safe and happy weekend.