Local governments in the Washington, D.C., region are planning a “full-scale” terror attack drill for Wednesday – an exercise that comes amid mounting tensions with North Korea and other threats.

The Metropolitan Washington Council of Governments confirmed in a press release that law enforcement and first responders will participate in the exercise “designed to prepare for the possibility of a complex coordinated terror attack in the National Capital Region.”

The drill prepares for an attack involving multiple locations and “teams of perpetrators” – and will be staged at six sites across the District of Columbia and the Virginia and Maryland suburbs.

It will involve hundreds of police and other emergency personnel and volunteer actors.

“Law enforcement officials practice and exercise their skills on their own regularly because that’s the best way to ensure we are always ready to respond quickly and professionally,” Scott Boggs, managing director of homeland security and public safety at COG, said in a statement.

He said the exercise set for Wednesday will “go one step further and stage a very realistic emergency event involving multiple sites and actors posing as the casualties.”

He stressed “there is no reason for residents to be alarmed because the exercise will occur in a controlled environment.”

The timing may be coincidental, but the drill comes as the Trump administration is working to address concerns about North Korea’s missile capabilities – and ahead of a major North Korea briefing for all 100 U.S. senators on the White House grounds later Wednesday.

After dining with the president, Republican Sen. Lindsey Graham told reporters Trump will not allow North Korea to build a nuclear-tipped missile capable of striking the United States.

"If I were North Korea, I would not underestimate President Trump's resolve to stop them from getting a missile to hit our homeland," he said.

The Trump administration has warned that all options, including a military strike, are on the table to block North Korea from developing a nuclear-tipped missile that could reach the U.S. mainland. But a pre-emptive strike against North Korea's nuclear and missile facilities isn't likely. The Trump administration is instead seeking to put pressure on North Korea with the help of China.

The Associated Press contributed to this report.