Vo Van Thuong, Vietnam's No.2 after its Communist Party General Secretary Nguyen Phu Trong, held talks with Xi after attending Beijing's Belt and Road Forum, Reuters reported.
"The two sides should adhere to the principle of joint consultation," Xi told Thuong, adding that China and Vietnam should capitalise on their geographical proximity and complementing industries.
China has traditionally strong ties with Vietnam since diplomatic relations were established in 1950, despite a brief war in 1979. Beijing has backed Hanoi’s fight against former colonial ruler France, and later, against Saigon and the US during the Vietnam War.
“Faced with the ever-changing international situation and arduous domestic development tasks, the two countries must not forget the original intention of their traditional friendship,” Xi told visiting Vietnam’s president Vo Van Thuong.
In September, US president Joe Biden visited Hanoi, as a result of the visit Vietnam elevated its ties with Washington to a comprehensive strategic partnership, putting its one-time enemy on par with Beijing and Moscow.
Chinese President Xi Jinping arrived in Moscow on Wednesday to pay a state visit to Russia and attend the celebrations marking the 80th anniversary of the Victory in the Soviet Union's Great Patriotic War.
Marking 50 years of diplomatic ties, Chinese President Xi Jinping and top EU leaders exchanged messages on 6 May affirming mutual respect and a commitment to deeper cooperation.