Taiwan–Vietnam relations are conducted on an unofficial level, as Hanoi adheres to a one-China policy and officially recognises the People's Republic of China only. However, this has not stopped bilateral visits and significant flows of migrants and investment capital between Taiwan and Vietnam. Taiwan has been the fourth largest source of foreign direct investment in Vietnam since 2006. Both countries maintain representative offices; Taiwan is represented by the Taipei Economic and Cultural Office in Hanoi and Ho Chi Minh City, while Vietnam is represented by the Vietnam Economic and Cultural Office in Taipei, both acting as de facto embassies. Vietnam is, to date, the only communist state to have relations with Taiwan.