It said there was no exchange of gunfire between the two sides in 250-kilometer-long, 4-km-wide DMZ, which is fortified with land mines, fences and guard posts. The US has around 28,500 troops stationed in South Korea. There was no peace treaty.
South Korea said Tuesday it is gauging an "appropriate" time to implement its planned aid to North Korea via United Nations agencies.
He was taken to hospital with gunshot wounds to his elbow and shoulder, South Korean officials said.
The South Korean military has raised its alert level in anticipation of a possible North Korean provocation following the defection.
South Korea has said the joint drill, due to finish on Tuesday, was in response to North Korean nuclear and missile provocations and to show any such developments by Pyongyang can be repelled with "overwhelming force".
As part of his continuing tour of Asia, Trump met with Japanese Prime Minister Shinzo Abe and Australian Prime Minister Malcolm Turnbull Monday in Manila to discuss the situation in North Korea.
Annual amnesty for unused antibiotics to tackle drug-resistant bugs
He is passionate about antibiotic awareness, because it's crucial that hospitals can continue to use antibiotics. Members of the public can also hand in their antibiotics at their local high street pharmacy.
Falcons RB Freeman 'unlikely to play' Monday after another concussion
The Falcons had meant to get both Freeman and Tevin Coleman more involved in the running game. If Freeman's concussion is serious then he'll likely miss the team's Week 11 game at Seattle.
MLB Awards: Aaron Judge unanimously named 2017 AL Rookie of the Year
Judge broke Mark McGwire's major league record for home runs by a rookie with 52, many of them jaw-dropping, tape-measure shots. The 22-year-old, who split time between first base and the outfield, batted.271 with 97 RBIs for the National League champions.
It was not immediately known how serious the soldier's injuries were or why he made a decision to defect.
Seoul says more than 30,000 North Koreans have defected to the South since the end of the Korean War in 1953. In 1998, a North Korean solider fled to South Korea via Panmunjom.
It marks the first massive joint drills since Seoul and Washington agreed last month to enhance rotational deployments of USA strategic assets to curb North Korea's nuclear and missile threats.
Assigned Strike force Units will conduct series of operations in worldwide waters to practice the US Naval force's unique ability to operate different carrier strike groups as a fully coordinated military team.
Separately on Monday, a 58-year-old man from Louisiana was arrested Monday when he entered a controlled area in Yeoncheon County on the North Korea border.