North Korean leader Kim Jong-un has visited a military unit to instruct ongoing winter training, calling for thorough preparations "to fight," Pyongyang's state media said Friday.

During his visit to Unit 1313 of the Korean People's Army, the young leader was briefed on "the situation of the new year combat and political drill," and then guided a firing exercise, according to the (North) Korean Central News Agency (KCNA).

It is the second time that Kim visited the military unit after the communist country kicked off the winter exercise earlier this week. He first visited the artillery unit 963 on Monday and guided training, the KCNA said.

The KCNA didn't disclose the date of Kim's latest visit and the location of the military unit.

"Next year should be the time of improving the quality of the training and achieving results in completing our combat readiness," Kim was quoted by the KCNA as saying.

With a goal to achieve national reunification in 2015, North Korea has geared up for all-out war by conducting tactical training and boosting its attack capabilities, according to the Seoul government.

The leader also stressed the need for "intensive training on the basis of concrete information on the enemy's situation and steadily improving the training methods and programs," instructing officers "to accelerate efforts to complete preparations to fight," it said.

Kim was accompanied by Hwang Pyong-so, director of the general political bureau of the Korean People's Army (KPA), Ri Yong-gil, chief of the KPA General Staff, and other commanding officers, according to the KCNA. (Yonhap)