Ninh Binh authorities held an international workshop on Thursday to assess the area's potential outstanding universal value and discuss the nomination process.
The proposed site is recognised for its tropical karst landscape, biodiversity, archaeology and cultural heritage. Van Long Nature Reserve is home to more than 200 Delacour's langurs, one of the world's rarest endemic primates.
Vietnamese and international experts are working to define the proposed site's boundaries, nomination timetable, legal framework and management plan.
Tran Tan Van, former director of the Vietnam Institute of Geosciences and Mineral Resources, said an executive summary had been completed for submission to UNESCO's tentative list, providing an initial legal basis for the nomination.
Research teams have focused on building scientific evidence under UNESCO criteria covering traditional human settlement, ecological and biological processes, and biodiversity conservation.
Experts have also drafted initial sections of the nomination dossier and management plan, while international specialists are helping prepare a preliminary assessment request and identify an appropriate boundary for the proposed site.
Researchers said the interconnected karst landscape is the last stronghold of the Delacour's langur. Archaeological remains and historic temples, communal houses and pagodas highlight the area's long history of human settlement.
Tran Song Tung, standing deputy chairman of Ninh Binh People's Committee, said preliminary studies had reinforced the site's importance for geology, tropical karst landforms, biodiversity, archaeology, history and culture.
He said the province aimed not only to secure World Heritage status but also to establish a conservation model balancing biodiversity, cultural heritage and sustainable development.
The province will continue working with government agencies, international organisations and scientists to complete the nomination dossier while strengthening conservation and landscape protection.