SEOUL -- A former sergeant in the North Korean military says that few of Pyongyang's soldiers have been captured fighting against Ukraine because they're told their families will be executed if they are caught alive.

North Korea recently sent some 3,500 additional soldiers to Russia's Far East for field training, a South Korean lawmaker said Wednesday, with the possibility of soon being dispatched to the front lines.

North Korea is no exception. Reports indicate that Kim Jong-un's soldiers, sent to fight alongside Russia, are learning how to use drones and improve battlefield tactics. This could have serious consequences for the region.

South Korea relies on security guarantees from the US to deter North Korean aggression, providing sites that host about 28,500 American troops. Earlier in March, a nuclear-powered US aircraft carrier docked at a South Korean port, prompting the sister of North Korean leader Kim Jong Un to denounce the deployment of strategic assets in the region.

South Korean and U.S. troops will begin their large annual joint military drills next week to enhance their readiness against North Korean threats

The exercise comes just days after North Korea warned of potential high-profile provocations in response to what it perceives as escalating U.S.-led aggression.