Video: Floating tank transporters deployed in Korea military drill More than 300 US soldiers and 95 South Korean soldiers participated in a joint river-crossing exercise in Yeoncheon on Thursday, constructing temporary floats for tanks and armoured vehicles to cross the Imjin River. A South Korean military official said 14 tanks and 16 armoured vehicles from both South Korea and the US were mobilized for the training. It was the first large-scale river-crossing training the troops have carried out in almost 10 years. The United States has about 30,000 troops in South Korea to support the country's 650,000-strong armed forces. Neighbour North Korea has some 1.2 million troops, mostly stationed along the border. North and South Korea are technically at war since the 1950-53 Korean War ended in a truce without a peace treaty.