Lu Kang, China’s Foreign Ministry spokesman, told reporters on Monday that he was unaware of the plan for the refugee camps, but he did not deny their existence.
“I haven’t seen such reports,” Mr. Lu said.
Changbai County officials did not answer telephone calls on Monday, and an executive at China Mobile in Changbai declined to discuss the matter.
The China Mobile document said that a manager of the company inspected five sites on Dec. 2 at the request of the Changbai County government.
The company was asked to ensure there was viable internet service in the areas that would be used for the camps. “Because the situation on the China-North Korea border has intensified lately, Changbai County government plans to set up five refugee sites in Changbai,” China Mobile said in the document.
The areas designated for the refugee camps were on state-owned land, and temporary housing had already been constructed at several sites, according to a local businessman who requested anonymity for fear of angering the local government.
Three county villages were named in the document as locations for the camps. The cities of Tumen and Hunchun will also house refugees, according to the businessman.
Tumen and Hunchun have for 20 years received defectors, who have managed to escape from North Korea into China. Many of those defectors travel on to Southeast Asia and eventually to South Korea.
Jilin Province is about 60 miles from Punggye-ri, the main North Korean nuclear test site. Fears of a nuclear war, or disaster, just miles away have set residents of the province on edge.
Last week, the Jilin Daily, a provincial newspaper, advised residents on how to react in case of a nuclear explosion or radioactive fallout.
The advice included washing off radioactive dust from exposed body parts and shoes, and taking iodine tablets. The article noted that when the United States dropped an atomic bomb on Hiroshima, Japan, in 1945, more than 70,000 people were killed. Modern weapons are many times more powerful.
China has refrained from imposing overly punitive sanctions on North Korea for fear of causing a collapse that would result in refugees flooding the economically vulnerable northeast. So far, China has resisted calls to cut off oil to North Korea, a move that would result in severe deprivation resulting in many people crossing the border.
Although China does not appear to have changed its basic position on maintaining stability, the increasingly hostile talk in Washington appears to be spurring contingency preparations.
Zheng Zeguang, the vice minister of foreign affairs, rushed to Washington last week to discuss what Chinese officials call the “black hole of confrontation” between the United States and North Korea.
As a result of the rising tensions, one of China’s most prominent experts on North Korea, called building the camps “absolutely reasonable.”
“It is highly possible that there is a conflict between North Korea and the United States now,” said Zhang Liangui, a professor of international strategic research at the Communist Party’s Central Party School. “What China does here is to be prepared for any kind of situation happening on the Korean Peninsula.”
In another sign of increased tensions, South Korea said on Monday that it would join the United States and Japan for a drill to practice tracking missiles launched from North Korean submarines.
Last month, North Korea tested an intercontinental ballistic missile that flew higher and longer than its previous tests. The North said that the missile could deliver nuclear warheads anywhere in the continental United States.