The Pentagon has abruptly canceled its participation at the Aspen Security Forum, stopping defense leaders from speaking at the high-profile national security conference because the event is not aligned with the goals of the Defense Department since President Donald Trump started his second term in office.

The Pentagon pulled senior Defense Department officials from the Aspen Security Forum on Monday, a day before the four-day summit in Colorado was set to begin. Why it matters: The bipartisan national security forum has attracted Republican and Democratic administration officials for years.