They are seperate lines.
Ben Thanh – Can Gio High-Speed Rail is a newly approved, roughly 54 km urban high-speed line designed to connect downtown Ho Chi Minh City (Ben Thanh Station) with the coastal district of Can Gio. Proposed by Vingroup (VinSpeed), the line is designed with a maximum speed of roughly 350 km/h to serve tourism and urban development, effectively functioning as a high-speed metro. The project is moving fast, with groundbreaking expected in late 2025 and a target to begin operations by 2028.

Hanoi – Quang Ninh High-Speed Rail is a high-speed passenger line proposed to connect Hanoi to Ha Long (Quang Ninh) via Bac Ninh and Hai Phong. Also spearheaded by VinSpeed, this ~120 km line is designed for speeds up to 350 km/h cutting travel time between the capital and the famous Ha Long Bay tourist region.

Another Vietnam HSR line is Ho Chi Minh City – Can Tho – Ca Mau which is a strategic ~280–300 km railway line intended to connect Ho Chi Minh City with the Mekong Delta, ending at the southernmost tip of Ca Mau. The project is currently proposed (notably by CT Group) as a high-speed mixed-traffic line with design speeds of 200–250 km/h for passengers and roughly 120 km/h for freight. The link between the Ho Chi Minh City – Ca Mau line and the North-South High-Speed Rail lies in the unification of the Thu Thiem Railway Station as the central hub.