"We'll be conducting more missile tests on a weekly, monthly and yearly basis", Vice Foreign Minister Han Song-Ryol told the BBC's John Sudworth in Pyongyang.
US President Donald Trump has said that will not happen, and stepped up pressure on the isolated North.
US Vice President Mike Pence used a visit to the heavily militarised border between the two Koreas Monday to declare "all options are on the table" in dealing with Pyongyang, the day after the North's latest failed missile test. On Thursday, the USA military dropped "the mother of all bombs", the largest non-nuclear device it has ever unleashed in combat, on caves and tunnels used by Islamic State in Afghanistan.
But while Tillerson's statement signaled a change in United States policy toward North Korea, Pence's came after the USA had launched two high-profile military assaults on targets in Syria and Afghanistan, both in their way unprecedented escalations of force by President Trump.
The U.S. Navy this month struck a Syrian airfield with 59 Tomahawk missiles after a chemical weapons attack.
North Korean Leader Kim Jong Un observes a target-striking contest by the Korean People's Army (KPA). The South Korean military found the first of them in 1978 and another in 1990.
One of the great worries associated with taking action against North Korea would be the ability of the Kim regime to retaliate against South Korea.
Trump wrote Sunday on Twitter that China was working with the United States on "the North Korea problem".
North Korea has taken "self-defensive" measures in response to USA threats of military action and these reflect Pyongyang's determination to "counter nukes and ICBM in kind", he said, referring to intercontinental ballistic missiles. While visiting US ally South Korea over the weekend, Pence warned that Washington's attitude toward North Korea has changed sharply.More news: Google Settles Russian Antitrust Case on Android Phones
"All options are on the table to achieve the objectives and ensure the stability of the people of this country", he told reporters as tinny propaganda music floated across from the North Korean side of the so-called demilitarised zone (DMZ).
"There was a period of strategic patience but the era of strategic patience is over", he said.
Vice Foreign Minister Han Song-Ryol told the BBC that North Korea believed its nuclear weapons "protect" it from the threat of U.S. military action.
Korean tensions have escalated following repeated North Korean missile tests and concerns that Pyongyang may soon conduct a sixth nuclear bomb test in defiance of United Nations sanctions.
"We need to apply pressure on North Korea so they seriously respond to a dialogue" with the global community, he said, urging China and Russian Federation to play more constructive roles on the issue. deforested stretch of North Korea from a lookout post in the hillside. Is the Korean peninsula headed for war?
With both governments in agreement on the goal, they are approaching it in markedly different ways, with the USA adopting the role of the bellicose "bad cop" while Chinese President Xi Jinping, calling North Korea to the negotiating table, plays the role of "good cop".
The Trump administration is hoping that China will help rein in North Korea in exchange for other considerations.
"If the U.S. is reckless enough to use military means it would mean from that very day, an all-out war".
Foreign companies bringing tour groups to North Korea, however, have seen no dip in demand.