Seoul and Washington made the already large-scale joint drills bigger than ever this year in response to the North's nuclear test in January and long-range rocket launch a month later.
Menacingly titled "Last Chance", the video released shows a submarine-launched nuclear missile laying waste to Washington and concludes with the US flag in flames.
The four-minute video romps through the history of US-Korean relations and ends with a digitally manipulated sequence showing a missile surging through clouds, swerving back to Earth and slamming down in front of Washington's Lincoln Memorial.
The US Capitol building explodes in the impact and a message flashes up on the screen in Korean: "If US imperialists budge an inch toward us, we will immediately hit them with nuclear (weapons)."
The North has issued similar videos in the past, including one in 2013 showing the White House in a sniper's crosshairs and the Capitol building exploding in a fireball.
The latest offering was published on the North's propaganda website DPRK Today and shows images from the Korean War, the capture of US spy ship Pueblo in 1968 and the first crisis over North Korea's nuclear programme in the early 1990s.
North Korea has been pushing to acquire a submarine-launched ballistic missile (SLBM) capability which would take its nuclear strike threat to a new level, allowing deployment far beyond the Korean peninsula and the potential to retaliate in the event of a nuclear attack.
It has conducted a number of what it says were successful tests of an SLBM, but experts have questioned the claim, suggesting Pyongyang had gone little further than a "pop-up" test from a submerged platform.
Tensions always rise on the Korean peninsula during the annual South-US military exercises, but have reached a particularly elevated level this year.
That is partly due to the nuclear test and the UN sanctions that followed, but also because of the first-time inclusion in the drills of an operation that envisages strikes to "decapitate" North Korea's top leadership.
Pyongyang has taken that as a direct threat to leader Kim Jong-Un and responded with increasingly abusive personal attacks on South Korean President Park Geun-Hye.
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