While almost 80% of the documents had not yet been identified, they reportedly included contingency plans for South Korean special forces and information on military facilities and power plants, it said.
Operational Plan 5015 is the latest Seoul-Washington protocol for war with Pyongyang, and contains plans to "decapitate" the North Korean leadership.
"Flying and training at night with our allies in a safe, effective manner is an important capability shared between the US, Japan and the Republic of Korea and hones the tactical prowess of each nations' aviators", Major Patrick Applegate said in a statement.
The North Korean party anniversary passed without any missile launches or nuclear tests, but officials are wary the North could engage in more provocations at any time, especially with China to begin its all-important Communist Party Congress on October 18. Defence officials refused to comment on Wednesday.
Russia, China call for restraint after Trump comment on North Korea
The two tweets come after Trump delivered cryptic comments on Thursday while taking photos alongside top military leaders. But the deal collapsed in 2003 after the U.S. accused North Korea of running a secret uranium nuclear program.
The United States has flown two supersonic heavy bombers over the Korean peninsula in a show of force against Pyongyang, staging the first night-time joint aviation exercises with Japan and South Korea.
"There is an urgent need for the military to change and update parts that were stolen by North Korea", Lee said.
Vice Foreign Minister Lim Sung-nam will hold strategic talks with visiting U.S. Deputy Secretary of State John Sullivan on October 18 in Seoul, according to Seoul's foreign ministry.
A pre-emptive strike against Pyongyang's leadership would be hard to undertake, but it's widely seen as the most realistic of the limited military options Seoul has to deny a nuclear attack from its rival.
Child left behind at Utah corn maze
A family left their 3-year-old boy at a corn maze in West Jordan, Utah and did not notice he was missing until the next morning. Investigators went to the house and said several families live there together with multiple children.
The Washington Post reports US President Donald Trump gave a directive for US Cyber Command to target hackers in North Korea's intelligence agency, the Reconnaissance General Bureau, early in his presidency.
He revealed that around 235 gigabytes of military documents had been stolen from the Defence Integrated Data Centre, and that 80% of them have yet to be identified. Other stolen data included contingency plans for South Korean special forces and information on military facilities and power plants, he said.
The report said Seoul has been hit by a number of cyber attacks in recent years trying to breach government and corporate websites and has since worked to bolster its cyber defense systems.
The U.S. has been pursuing a strategy of "maximum pressure" on North Korea, applying diplomatic and economic pressure multilaterally and unilaterally.
China ready to maintain peace with India along the border
The Defence Minister reiterated the government's resolve to give further impetus to development in the border areas. Meanwhile, Global Times - which has a reputation for criticising India - also carried an editorial.