Before Transformers came about in 1984, Japan unleashed the Diaclone toy line, which was the obvious precursor to Transformers itself. However, South Korea planned to cash-in on the toy franchise by releasing an anime movie in 1986.
That's right! Micro Commando Diatron 5, as the movie was called, features giant robots with designs similar to that of Diaclone's toy designs. It also has them with human protagonists fighting against evil aliens from outer space. For example, the big red and white robot you see on the film's poster almost looks like what would later become Optimus Prime, except with a different color scheme. The movie was dubbed into English and was distributed by Hong Kong filmmaker Joseph Lai in the United States and Europe.
There were two other South Korean movies that were similar to Diaclone, of which both were released in 1984. Phoenix-bot Phoenix King features a transformable robot fire engine that was similar to that of the Diaclone No. 11 toy. The film was dubbed into English by Joseph Lai and was distributed in the United States and Europe, given the title Defenders of Space. Video Ranger 007 was mostly based off of the Japanese anime Video Warrior Laserion, but the protagonist robot's design on the poster was not like that of Laserion, but rather had a Diaclone-type design. It also transforms into a jet plane.