More than 200 million cell phones across the country will buzz with a message from the Trump administration today — whether Americans like it or not.

FEMA will test its “Presidential Alert” system on Wednesday afternoon. The test message was originally scheduled for September but was pushed back to Wednesday at 2:18 p.m. EDT.

The service is meant to work much like an Amber Alert, according to the agency, providing Americans with crucial information during emergency situations. The Federal Emergency Management Agency (FEMA), which will send the alert, said the messages would bear the headline “Presidential Alert,” and that phones will make a loud tone and have a special vibration.

“THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed,” a brief message will read, according to FEMA.

But the name has irked opponents of President Trump — who has a taste for tweeting out daily to his 55 million followers on Twitter — with many bemoaning their inability to opt out of the message.

“This narcissist lunatic is going to treat this service like his Twitter I can picture it now,” one user tweeted.

“Why is this damn national text message system even a thing?” another asked. “Trump is just looking for another way to have control over us.”

A third user decried the routine test of the emergency alert system as “Hitlerian in every way.”

In a call with reporters on Tuesday, a FEMA rep pointed out that the president will not be personally sending the alert.

“You would not have a situation where any sitting president would wake up one morning and attempt to send a particular message,” the rep explained.

An actual alert would be used for an impending missile attack or other national emergency.

Then-President Barack Obama signed a law in 2016 requiring FEMA to create a system allowing the president to send cellphone alerts regarding public safety emergencies.

Federal Communications Commissioner Mike O’Rielly told reporters Tuesday that an April 5 regional test of the emergency alert system in the Washington area showed some potential issues.

He said some people did not receive alerts on some devices during that test. “We’re trying to analyze that,” O’Rielly said.

The country’s wireless emergency alert system has issued over 36,000 alerts for situations such as missing children, extreme weather and natural disasters since 2012, but never a presidential directive.

Cellphone users can opt out of natural disaster or missing children alerts, but not presidential alerts. Verizon Communications Inc. said nearly all of its mobile phone handsets are capable of getting alerts.

Government officials estimated that the alert would reach upwards of 225 million US cellphones, or around 75 percent of all phones. They said a person on a call lasting 30 minutes may not get the alert as with phones with an active data connection.

With Post wires