"South Korea has been living under such threats from the past, and we are always prepared for it," South Korean Unification Minister Ryoo Kihl-jae told CNN on Wednesday. He called the current climate "a very ordinary situation."
"North Korea may launch missiles at any time, and our military is fully prepared for it," he said.
But the North's fiery words appear to have had an effect on the American public, with 41% of those surveyed saying they see the reclusive nation as an immediate threat to the United States, according to a recent CNN/ORC International poll.
That's up 13 percentage points in less than a month, CNN Polling Director Keating Holland said.
"If North Korean leader Kim Jong Un wanted to get the attention of the American public, his strategy is starting to work," Holland said.
Andrei Lankov, a professor of history at Kookmin University in Seoul, noted the varying levels of concern in an opinion article for The New York Times published Tuesday.
"The farther one is from the Korean Peninsula, the more one will find people worried about the recent developments here," he said.
The tense situation does appear to have prompted some Chinese tour groups to call off upcoming trips to North Korea.
Hong Lei, a spokesman for the Chinese Foreign Ministry, said Wednesday that some agencies and tourists had canceled plans, but he said the Chinese-North Korean border continued to operate normally.
Western tourism agencies that organize visits to North Korea haven't so far reported any changes to their activities.
A troubled industrial zone
The most tangible signs of disruption are in the Kaesong Industrial Complex, the manufacturing zone on the North Korean side of the border where more than 120 South Korean companies operate.
Last week, the North started blocking South Korean personnel from crossing the border back into the complex. And this week, it said it was pulling out the more than 50,000 North Koreans who work inside the zone and temporarily suspending activities there.
It had blocked the border crossing previously, in 2009, but pulling out the workers was a new step.
As of Wednesday lunchtime, only a few hundred South Koreans remained inside the complex, according to South Korean authorities, down from more than 800 before the North started restricting entry.
Also on Wednesday, South Korea accused the North of carrying out a wave of cyberattacks that paralyzed the networks of major South Korean banks and broadcasters last month. It is the first time that Seoul has formally pointed the finger at Pyongyang for the hacking, which affected more than 48,000 computers.