The Journalist Association of Korea also asked Alexander Vershbow to apologize for his remarks calling on South Koreans to be alert against the North. They said the comments were an "intrusion in domestic affairs."
"Ambassador Alexander Vershbow should apologize for his remarks aimed at interfering in South Korean affairs," said the association, which has some 6,000 members nationwide.
The statement comes a day after the U.S. envoy said South Korea should be worried over the North, which "is wasting its resources developing nuclear weapons and counterfeit bills, drug-dealing and money-laundering to survive."
"I think all South Koreans should be worried about a regime that treats its own people so badly," he said in a message posted on the U.S. Embassy's community Web site, Cafe USA.
Last month, he labeled North Korea a "criminal regime," drawing harsh criticism from Pyongyang as well as pro-unification activists in the South.
"Isn't it interference in domestic affairs for an ambassador to tell the people in a country where he works what to do?" the journalists group said in a statement. It urged Vershbow to "stop making anti-North Korean remarks that do more harm than good."