A South Korean lawmaker says North Korean computer hackers stole a large number of classified military documents from the South, including plans to "decapitate" the North's leadership.
Lee Cheol-Hee of the ruling Democratic party cited South Korean defense officials Tuesday.
Officials believe hackers broke into a South Korean military data center in September 2016 and made off with the secret documents.
They include planned attacks on North Korean leader Kim Jong Un to "decapitate" the North's leadership in case war breaks out.
"Also among them were contingency plans for the South's special forces, reports to allies' top commanders, and information on key military facilities and power plants," Lee told the Yonhap news agency.
He says 80 percent of the stolen documents have yet to be identified.
Meeting with reporters in Washington, Pentagon spokesman Colonel Rob Manning would not confirm or deny the documents were stolen.
"What I am going to tell you is that the [South Korean]-U.S. alliance, that bilateral entity, is there to deal with those types of situations and safeguard against them."
Manning said the Pentagon is confident in the security of its operations in Korea, including the ability to deal with any threat from the North.
News of the stolen military documents comes a day after the United Nations announced it has banned four ships that were transporting prohibited goods to and from North Korea from entering any port in the world.
A maritime database that monitors naval vessels identified the banned vessels as the Petrel 8, which is registered in Comoros; the Hao Fan 6, which sails under the flag of Saint Kitts and Nevis; and North Korea's Tong San 2. The fourth ship, the Jie Shun, was not registered with any country.
North Korea is barred from exporting coal, iron, lead and seafood because of its recent test of an apparent hydrogen bomb and its refusal to stop testing intercontinental ballistic missiles.
VOA's Kenneth Schwartz contributed to this report.