In response, President Donald Trump has warned North Korea repeatedly that if it takes such action, the USA will hit back.
Its military officials intend for them to land a little outside the 14-mile mark that is accepted as the limit of territorial waters, North Korean state media said, subject to Kim Jong-un's agreement.
But restraint was not the word of the day on Friday as Trump sent out a cascade of unscripted statements, including what appeared to be another red line - the mere utterance of threats - that would trigger a US attack against North Korea and "big, big trouble" for Kim.
North Korea this week announced a detailed plan to launch a salvo of ballistic missiles toward the U.S. Pacific territory, which is a major military hub and home to U.S. bombers.
North Korea warned that a plan to attack Guam would be in place by mid-August and dismissed Trump's threats as a "load of nonsense", according to reports. "They are here to protect the islands, just in case something happens".
"The U.S. should clearly face up to the fact that the ballistic rockets are now on constant standby", said the KCNA. Guam is also home to the Terminal High Altitude Area Defense (THAAD) missile system, which can knock out intermediate-range missiles as their approach the island.
North Korea is actually capable of hitting Guam with its Hwasong-12.
Trump declined to say whether the U.S.is considering a pre-emptive military strike as he spoke to reporters before a briefing with his top national security advisers. The chilling two-page fact sheet details what citizens of the 162,000-populated island that houses 6,000 US troops should do to survive the worst outcome of the boiling tensions between Washington and Pyongyang.
Naval Base Guam is an important outpost for US fast-attack nuclear powered submarines that are a key means for gathering intelligence in the region, including off the Korean peninsula and in the South China Sea where China has been building military bases on man-made islands that have stirred tension across Asia.
It was not the first time Guam has been put on notice and similar threats made since 2013 led to the US military permanently deploying a Terminal High Altitude Area Defense (THAAD) interceptor system on the tiny island.
Residents of Guam have been issued with advice on what to do if North Korea launches an attack.
"I'm glad you're holding the helm, Sir", he said.
Guam is about 2,100 miles (3,380 kilometers) southeast of Pyongyang and 3,800 miles (6,115 kilometers) west of Honolulu in the Pacific Ocean. Chamorros are the indigenous people of Guam.
FILE - In this file image made from video by North Korea's KRT released on July 28, 2017, North Korean leader Kim Jung Un, second from right, gestures at the site of a missile test at an undisclosed location in North Korea.
"Let her speak for Germany", Trump said, when asked about the comment.