North Korea appears to be preparing to deploy additional troops and military equipment to Russia, possibly including suicide drones, in support of Moscow's war against Ukraine, South Korea's military said Monday, Yonhap News Agency reports.

"A comprehensive assessment of multiple intelligence shows that North Korea is preparing to rotate or increase the deployment of troops [in Russia]," the South’s Joint Chiefs of Staff (JCS) said.

The assessment came as North Korea is believed to have sent thousands of troops to fight for Russia in its war against Ukraine, with the number of casualties estimated to be around 1,100, according to the South's spy agency.

"There are also some signs of [the North] moving to manufacture and supply suicide drones, first unveiled during [the North’s leader] Kim Jong-un's on-site inspection in November," the JCS added.

Last month, the North's state media reported that Kim observed an on-site test of various types of suicide attack drones and called for the full-scale production of the weapons, Yonhap reported.