The capital city of the United States is gearing up for Saturday's military parade to honor the 250th birthday of the Army and the 79th birthday of President Donald Trump.

"We're preparing for an enormous turnout," Matt McCool of the Secret Service's Washington Field office, was quoted on Monday by The Associated Press as saying. More than 18 miles of "anti-scale fencing" would be erected and "multiple drones" would be in the air, according to the officer. The entire District of Columbia is normally a no-fly zone for drones.

Army officials have estimated around 200,000 attendees for the evening military parade, and McCool said he was prepared for "hundreds of thousands" of people.

A total of 175 magnetometers would be used at security checkpoints controlling access to the daytime birthday festival and the nighttime parade. Metropolitan Police Department chief Pamela Smith predicted major impacts to traffic and advised attendees to arrive early and consider forgoing cars for the Metro.

The military parade has been designated a National Special Security Event, similar to a presidential inauguration or state funeral. That status is reserved for events that draw large crowds and potential mass protests. It calls for an enhanced degree of high-level coordination among D.C. officials, the Federal Bureau of Investigation, Capitol Police and Washington's National Guard contingent, with the Secret Service taking the lead.

The Army birthday celebration had already been planned for months. But earlier this spring, Trump announced his intention to transform the event, which coincides with his 79th birthday, into a massive military parade complete with 60-ton M1 Abrams battle tanks and Paladin self-propelled howitzers rolling through the city streets.