Why are there trade tensions with China?

China has revolutionized its economy very quickly. With an increasing number of large corporations and technological advancements, plus the potential size of their economy, they show to be a future thread to passing the USA as the world superpower. Since the US is power hungry they want to stop this rise. So far they have been trying to slow their economy with tariffs and export decreases, but since the US relies on so much from China they have to play economy scale chess. On top of all this the Chinese government has a bad history of humans rights violations and threatening territories sovereignty. This allows the US to impose stricter trade deals with the help of the UN.