North Korea said on Jan. 8 it would consider test-launching an intercontinental ballistic missile "at any time" and at any location the country's leader Kim Jong Un chooses.
The news comes after Kim declared on New Year's Day North Korea was on the brink of testing an ICBM whose nuclear weapon could reach the continental United States, CNN reports.
North Korea officials blamed American foreign policy for the country's increasingly aggressive stance, NBC News reports.
"The U.S. is wholly to blame for pushing [North Korea] to have developed an ICBM as it has desperately resorted to anachronistic policy hostile toward [North Korea] for decades to encroach upon its sovereignty and vital rights," said an anonymous Foreign Ministry spokesman.
The sentiment has disturbed some U.S. officials.
"Their nuclear weapons and ballistic missile defense programs are a serious threat to us," Defense Secretary Ash Carter said on NBC's "Meet the Press."
He also said the department will shoot down a North Korea missile launch or test "if it were coming towards our territory or the territory of our friends and allies."
Besides the U.S., North Korea's words have also alarmed neigboring countries South Korea and China.
"If North Korea disregards our warning and launches an ICBM, it will face more powerful and thorough sanctions and pressure by the international community," South Korean Defense Ministry spokesman Moon Sang-gyun said.
Meanwhile, U.S. President-elect Donald Trump has issued a similar comeback on his Twitter account.
"North Korea just stated that it is in the final stages of developing a nuclear weapon capable of reaching parts of the US," he wrote. "It won't happen!"
Trump and North Korea's threats come at a point some thought the future Trump presidency may ease relations.
Before this threat, North Korea reportedly had not issued any threats since October -- a good sign for some.
"[Trump could be the] American president who prevented North Korea from obtaining the ability to strike the U.S. with a nuclear weapon," claimed, Tong Zhao, an associate at Carnegie-Tsinghua Center for Global Policy in Beijing.
Zhao was referring to Trump's controversial comments in June that he would be open to invite Kim to the U.S. to talk.