North Korea on Tuesday urged foreign companies and tourists in South Korea to evacuate, saying the two countries are on the verge of a nuclear war. The new warning appeared to be an attempt to scare foreigners into pressuring Washington and Seoul to act to avert a conflict.

Analysts see a direct attack on Seoul as extremely unlikely, and there are no overt signs that North Korea’s army is readying for war, let alone a nuclear one.

Despite the warnings of an impending war, there was no sense of panic in North Korea’s capital, Pyongyang, on Tuesday.

Scores of people of all ages were armed with shovels, not guns, as they planted trees in a forestation campaign. The national flag fluttered across the city as North Korea marked the 20th anniversary of late leader Kim Jong Il’s appointment as chairman of the National Defense Commission.

The call from the Asia-Pacific Peace Committee for foreigners to leave South Korea was the latest in a series of statements aimed at ramping up anxiety abroad about tensions on the peninsula.

“The situation on the Korean Peninsula is inching close to a thermonuclear war due to the evermore undisguised hostile actions of the United States and the South Korean puppet warmongers and their moves for a war against” North Korea, the committee said in a statement carried by state media.

White House spokesman Jay Carney called the statement “more unhelpful rhetoric.”

“It is unhelpful, it is concerning, it is provocative,” he said.

North Korea has been girding for a showdown with the U.S. and South Korea, its wartime foes, for months. The Korean War ended in 1953 with an armistice, not a peace treaty, leaving the peninsula still technically at war.

Adm. Samuel Locklear, commander of U.S. Pacific Command, told the Senate Armed Services Committee in Washington on Tuesday that he concurred with assessments calling the tension between North Korea and the West the worst since the end of the Korean War.

“The continued advancement of the North’s nuclear and missile programs, its conventional force posture, and its willingness to resort to asymmetric actions as a tool of coercive diplomacy creates an environment marked by the potential for miscalculation,” Locklear told the panel.

He said the U.S. military and its allies would be ready if North Korea tries to strike.

“Do we have the capability to intercept a missile if the North Koreans launch within the next several days?” Sen. John McCain, R-Ariz., asked the admiral.

“We do,” Locklear answered.

Heightening speculation about a provocation, foreign diplomats reported last week they had been advised by North Korea to consider evacuating by Wednesday.

However, Britain and others said they had no immediate plans to withdraw from Pyongyang.

South Korean President Park Geun-hye, who has sought to re-engage North Korea with dialogue and humanitarian aid since taking office in February, expressed exasperation Tuesday with what she called the “endless vicious cycle” of Seoul answering Pyongyang’s hostile behavior with compromise, only to get more hostility.

U.S. and South Korean defense officials have said they’ve seen nothing to indicate that Pyongyang is preparing for a major military action, and there was no sign of an exodus of foreign companies or tourists from South Korea.

Still, the United States and South Korea have raised their defense postures, as has Japan, which deployed PAC-3 missile interceptors in key locations around Tokyo on Tuesday as a precaution against possible North Korean ballistic missile tests.

In Rome, U.N. Secretary-General Ban Ki-moon described the tensions as “very dangerous” and said that “any small incident caused by miscalculation or misjudgment” may “create an uncontrollable situation.”

Also Tuesday, citing the tension, North Korea pulled out more than 50,000 workers from the Kaesong industrial park, which combines South Korean technology and know-how with cheap North Korean labor. It was the first time that production has been shut down at the complex, the only remaining product of economic cooperation between the two countries that began about a decade ago when relations were much warmer.

Chu Kang Jin, a Pyongyang resident, said everything is calm in the city.

“Everyone, including me, is determined to turn out as one to fight for national reunification … if the enemies spark a war,” he said, using nationalist rhetoric employed by many North Koreans when speaking to the media.