TOKYO -- Tensions on the Korean Peninsula have risen even further after claims the reclusive country may have succeeded in creating a nuclear warhead small enough to be mounted on a ballistic missile.
The claims, if they turn out to be true, raise the genuine possibility of a direct nuclear attack on U.S. soil.
Washington may be officially sticking to its stance of taking the diplomatic route, but the military option will undoubtedly be considered an increasingly realistic option at this stage.
So far, the U.S. has worked on the presumption tensions would be resolved by China joining in the diplomatic push before Pyongyang can deploy nuclear-equipped intercontinental ballistic missiles.
According to a U.S. security expert close to the administration, Washington initially set a two-year timeline for the process.
Recent developments seem to have made it clear this grace period was unrealistic and prompted a rethink on its North Korea strategy.
U.S. officials will now be hastily examining various military options as backup, ranging from an all-out attack to targeted bombings.
President Donald Trump took the rhetoric up a notch on Tuesday by suggesting the use of force may have become more likely -- although he had never ruled out the possibility.
"North Korea best not make any more threats to the United States," Trump said during a press briefing. "They will be met with fire and fury like the world has never seen."
The U.S. Department of Defense now expects North Korea could deploy nuclear warheads as early as next year after the country conducted two test launches of ICBMs.
The Washington Post reported on Tuesday that the U.S. Defense Intelligence Agency has said in a classified assessment it believes North Korea has successfully produced a miniaturized warhead that can fit on a ballistic missile.
If this proves to be true, all the country would need is to develop the technology to stop the warhead burning up on re-entry to the atmosphere, which would allow it to perfect a nuclear weapons system capable of attacking the U.S. mainland.
If war breaks out with North Korea, the number of casualties in South Korea would likely reach several tens of thousands to several hundred thousands, according to one estimate. With over 200,000 Americans living in the country, Washington remains reluctant to take the military option.
However, a U.S. official has said there is no way the country would tolerate a North Korean deployment of nuclear ICBMs.
A diplomatic source said "Washington may decide to take the risk of tremendous casualties to attack North Korea if the threat of [one of] its missile hitting major U.S. cities escalates."