US officials warn that North Korea will test another missile soon

North Korea has made preparations for yet another missile test within the coming days, US officials have told Fox News.

"The test could come as early as the end of the month," said an unnamed official. Another official told Fox that a US WC-135 Constant Pheonix "nuclear sniffer" plane would patrol the area to detect possible nuclear activity.

The Pentagon, as well as its Japanese and South Korean counterparts, has been closely monitoring North Korea after a string of high-profile and alarming moves within its nuclear infrastructure.

Most recently, Japan detected two missile launches in North Korea that exploded "within seconds" after takeoff, CNN reported. Before that, North Korea tested a "saturation attack" - a salvo of four missiles meant to overwhelm US and allied missile defenses - with much more success.

Jeffrey Lewis, founding publisher of Arms Control Wonk, told Business Insider that North Korea's ultimate intention with its nuclear program is to create a thermonuclear weapon that can hit the mainland US.

The increased pace of tests in 2017 shows North Korea is perhaps more serious than ever about hitting this goal, which it is increasingly moving closer to achieving.

Meanwhile, the US has openly floated military action against North Korea, which experts tell Business Insider could easily cost millions of lives and result in the first use of nuclear weapons since World War II.