The Kim Jong-Un regime has said it now has the capability of striking the US mainland after two successful intercontinental ballistic missile (ICBM) tests last month.
Critics say the tweet sharply increases the likelihood of a conflict between the countries, as North Korea could misinterpret Trump's rhetoric and US military maneuvers as signs of impending invasion and launch a preemptive attack.
Market volatility jumped as traders reacted to growing tensions between the United States of America and North Korea despite US Defence Secretary James Mattis saying that any conflict between the two nations would be "catastrophic".
"The DPRK must choose to stop isolating itself and stand down its pursuit of nuclear weapons", Mattis said.
"Guam's leaders say the threat level hasn't gone up following North Korea's latest threat".
Earlier Wednesday, U.S. Secretary of State Rex Tillerson defended Trump's remarks.
"As tensions escalate with North Korea, we must remind ourselves that military action, and risking American soldiers' lives, should never be the first response".
China has urged the United States and North Korea on Friday to be "cautious" with their words and actions after the two sides stepped up their bellicose rhetoric over Pyongyang's weapons programme.
Pyongyang on Thursday announced it was finalising a plan to fire four missiles near the USA territory of Guam.
"We want to use diplomacy [and] that's where we've been, that's where we are right now and that's where we hope to remain, Mattis said during a press briefing on Thursday". But when asked how he would gauge the threat from North Korea, the Secretary said it is "a threat to world peace and global order" and that the human toll from such an attack would be "catastrophic".
South Korean President Moon Jae-in is expected to deliver a speech next week to mark Liberation Day, when the Korean peninsula secured freedom from the rule of Japan.