A South Korean man suspected of spying on North Korea for his government has pleaded guilty to charges that he repeatedly lied about his activities to the FBI.

Park Il Woo pleaded guilty in federal court on Friday to lying about his role as a South Korean agent, the U.S. attorney's office in Manhattan said. Park, who also goes by the name Steve Park, was never charged with espionage.

Prosecutors have said that Park made 50 trips to China and the Korean peninsula over the last several years and had appeared to be engaged in espionage type activities for at least five years.

Park is a South Korean citizen living in the United States. U.S. law requires anyone acting as an agent of a foreign government to register with the attorney general and disclose the nature of the activity.

An FBI agent said in court papers that Park had not registered, though he had admitted meeting with South Korean intelligence officers and agreeing to be paid to travel to North Korea to gather information for South Korea.

According to court papers, Park met with the FBI once in 2005 and twice this year, each time lying about his contacts with or knowledge of certain South Korean officials.

Park's lawyer has said her client is a law-abiding resident, and this case was an instance in which "what appears to be quite bad turns out to be much less."