The South will not succumb to scare tactics and rush into any new peace agreements to stop the North's conduct, he added. He admonished North Korea to open a different kind of dialogue.
The Korean war ended in 1953 with an armistice agreement, not a peace treaty.
Pyongyang has consistently demanded a full peace treaty, and it also wants direct talks with the United States, which Washington has resisted, preferring instead multilateral discussions.
Missile test put off
The United States is delaying a long-planned missile test to avoid any misperceptions by North Korea amid mounting tensions, a senior U.S. Department of Defense official said Saturday.
Postponing the launch of the Minuteman III intercontinental ballistic missile, initially scheduled for Tuesday at Vandenberg Air Force Base in California, was "prudent and wise," the official said on condition of anonymity.
The missile test had nothing to do with North Korea, but the United States decided to hold off "given recent tensions on the Korean Peninsula," the official said.
"The U.S. will conduct another test soon and remains strongly committed to our nuclear deterrence capabilities," said the official, who was not authorized to publicly release details of the launch.
Embassies staying put
Word of the launch delay comes amid bellicose posturing and threats that have grown more dramatic by the day on the Korean Peninsula, including North Korea's warning to foreign diplomats in Pyongyang that if war breaks out, it cannot guarantee their safety.
On Friday, officials met with ambassadors to ask whether they needed help evacuating their personnel, several diplomatic missions said.
The same concern apparently does not extend to foreign tourists.
Amanda Carr, who works for a British travel company, wrapped up a pleasure tour of North Korea with a group of 20 tourists Saturday. Before leaving the country, they were able to take in a rally in Pyongyang.
The British Embassy in North Korea gave her company, Koryo Tours, some guidance in light of the international tensions. "We've been advised to continue with the tours," Carr said.
Her North Korean partners -- from the state's travel agency -- continue to accept tourists, she said. And their demeanor is friendly, as it always has been.
Russia, a traditional ally of North Korea's, may consider an evacuation of staff because of the tensions, Russian state media said.
The Swedish Embassy will remain open. It represents the concerns of the United States in North Korea and helps its citizens traveling there.
British, French and German diplomats also have no immediate plans to leave.
Meanwhile, U.S. Secretary of State John Kerry will visit Asia next week and is expected to discuss potential diplomatic incentives for North Korea once it stops its threatening rhetoric, senior administration officials told CNN on condition of anonymity.
"Secretary Kerry agrees that we have to have a robust deterrent because we really don't know what these guys will do," said one senior official, who was not authorized to speak on the issue.
"But he also knows that the North Koreans need a diplomatic off-ramp and that they have to be able to see it."
New reports of missile movements in North Korea have triggered military counteractions by South Korea and the United States.
South Korea's semiofficial Yonhap news agency reported that the missiles were ready to launch, citing military sources in Seoul. They are probably Musudan missiles, U.S. officials said. They would have a 2,500-mile range and could threaten South Korea, Japan and Southeast Asia.
It is believed that a North Korean missile launch would be a "test" launch rather than a targeted strike.