North Korea could react to a potential U.S. strike by targeting South Korea or Japan, and officials in Tokyo and Seoul have been ill at ease with the more bellicose language deployed by Trump's administration.
But officials at Pentagon are believed to be unsure how North Korea would respond if U.S. the shoots down a test missile.
Ministry official Kim Chang Min also said in the interview in Pyongyang that the United Nations, the Security Council and big countries ignored South Korean missile launches and Japanese surveillance satellites. "We are with you 100 percent", he continued.
"If the U.S. is reckless enough to use military means it would mean from that very day, an all out war".
He said North Korea's next nuclear test would take place "at a time and at a place where our headquarters deems necessary".
Lu's comments came after North Korea's deputy ambassador to the United Nations and its vice Foreign Minister reportedly said that a new nuclear test was under preparation and more missile tests would be conducted on a weekly, monthly and yearly basis.
President Donald Trump in Washington and Pence at the Demilitarized Zone between North and South Korea have signaled a forceful US stance on North Korea's recent actions.
Pence also said the USA would protect freedom of navigation in the South China Sea, the sea lanes vital to global shipping where China has been staking claim to disputed territory.
While Japan's trade surplus with the U.S.is much smaller than China's, Trump has decried the imbalance, especially in auto exports.
Asked whether he had ruled out the possibility of launching a military strike against North Korea, Trump said he did not wish to reveal his plans.
Chinese Foreign Ministry spokesman Lu Kang said all parties should make efforts to resolve the situation.
The vice president met Japanese officials, including Prime Minister Shinzo Abe, and reassured them of the USA commitment in the face of possible threats posed by North Korea.
Speaking with reporters on his way to the Middle East, Mattis said the most recent test was not an intercontinental ballistic missile but still a reckless move.
The Trump administration has signaled a forceful US stance on North Korea's recent actions, dispatching Pence to the Demilitarized Zone dividing North and South Korea on Monday in a show of American resolve.
In his interview on Tuesday, Trump said past presidents had put off dealing with North Korea. But it's becoming increasingly clear that President Trump might not know the name of North Korea's leader.
"But I would be concerned he would feel the need to react strongly, as he would not want to appear weak", Denmark added.
"The people of North Korea, the military of North Korea should not mistake the resolve of the United States of America to stand with our allies".