South Korean and U.S. forces conducted a joint drill Wednesday, the first South Korea-led exercise as the allies prepare for the planned transfer of Seoul's wartime operational command.

A Republic of Korea (ROK) tank releases smoke bombs on Wednesday during joint military exercises with the US in Paju, near the demilitarized zone, about 45 km north of the ROK capital, Seoul.

More than 800 troops from South Korea's tank battalion and two U.S. squadrons engaged in mobile training and a free-fighting training at the Mugeonri military training field, north of Seoul.

South Korea mobilized 40 K-1 tanks, four K-200 and K-242 armored cars, three K-277 armored vehicles, two self-propelled anti-aircraft guns and eight rescue vehicles. 28 U.S. M2A3 Bradley fighting vehicles and rescue vehicles were also involved.

The four-day exercise marked the first one commanded by the South Korean military, which is scheduled to retake its wartime operational control, currently held by the U.S., in 2015.

Seoul's wartime operational control was given to the U.S.-led United Nations Command at the outbreak of the 1950-53 Korean War, which was later transferred to the South Korea-U.S. Combined Forces Command (CFC).

Some 28,500 U.S. troops have been stationed here following the war.