The South Korean Defense Ministry says the government will soon sign a deal with the United States to increase military exercises and boost preparedness in case of a possible North Korean aggression.

South Korea's Deputy Defense Minister Lim Kwan-Bin said Wednesday the threat of provocation by North Korea remains a constant possibility, as Kim Jong Un moves to solidify his power following the death of his father, Kim Jong Il.

South Korean officials say the joint operational plan was agreed to in October and is expected to be signed later this month.

The United States and South Korea already conduct joint military exercises, but officials in Seoul say the new deal would specify how often they would take place.

About 28,500 U.S. troops are currently stationed in South Korea to help guard against the threat of an attack by the nuclear-armed government in Pyongyang.

Tensions between the two Koreas has been high since Seoul accused Pyongyang of sinking a warship near the disputed sea border, known as the Northern Limit Line. Forty-six South Korean sailors were killed in the March 2010 attack.

Relations worsened after the North bombarded South Korea's Yeonpyeong island in November 2010, killing four people.

Since the death of its former leader Kim Jong Il in December, North Korea has maintained its hard line against the South.

Pyongyang has already promised never to deal with the current administration of South Korean President Lee Myung-bak. It also threatened retaliation against Seoul for what it considered disrespect during the mourning period for Mr. Kim.