The 10th China-Vietnam border defense friendship exchange began on Monday with the arrival of a Vietnamese naval fleet in South China's Fangchenggang, Guangxi Zhuang Autonomous Region. Officers and sailors from the Chinese Navy extended a warm welcome to the Vietnamese guests. The two sides later engaged in friendly exchanges, including a sports and souvenir exchange. In the coming days, the two navies will conduct the 40th joint patrol in the Beibu Gulf. The joint patrols have spanned two decades since China and Vietnam signed an agreement on joint patrols in the Beibu Gulf waters in 2005.