China has had a long and complex trade relationship with the United States. In 2000, the United States Congress approved "permanent normal trade relations" (PNTR) with China, allowing Chinese exports in at the same low tariffs as goods from most other countries. China has a significant trade surplus with the United States, its most important export market. In the early 2010s, US politicians argued that the Chinese yuan was significantly undervalued, giving China an unfair trade advantage.