Vietnam's Prime Minister sought support for the nation's stance in the East Sea, internationally known as the South China Sea, when he met South Korea's foreign minister in Hanoi on Monday.
Vietnam is the country most openly at odds with China over the waterway since the Philippines pulled back from confrontation under President Rodrigo Duterte.
"The Prime Minister proposed that South Korea continue its support over the position of Vietnam and Southeast Asia on the East Sea issue and to help the country improve its law enforcement at the sea", the government said in a statement on its website after the meeting between Prime Minister Nguyen Xuan Phuc and South Korea's Foreign Minister Yun Byung-se.
The statement did not say whether South Korea backed Vietnam's position on the East Sea.
Yun did affirm his country's willingness to promote ties despite instability in South Korea after the ousting of President Park Geun-hye over a graft scandal.
South Korea is Vietnam's biggest foreign investor thanks to companies like Samsung.
South Korea and China are currently in dispute over deployment of the U.S. anti-missile defence system. The former on Monday has complained to the World Trade Organization about Chinese retaliation against its companies over the deployment.
Last week, Vietnam demanded China stop sending cruise ships to the area in response to one of Beijing's latest moves to bolster its claims to the strategic waterway.
China claims 90 percent of the potentially energy-rich South China Sea. Brunei, Malaysia, the Philippines, Vietnam and Taiwan lay claim to parts of the route, through which about $5 trillion of trade passes each year.