HANOI -- Vietnam aims to start building two high-speed railway lines linking its capital Hanoi with China before 2030, the Ministry of Planning and Investment said, another sign of a recent warming of ties between the two neighbours.

China is Vietnam's largest trading partner and a vital source of imports for its manufacturing sector. The two countries are already connected via a system of highways and two railway lines that are old and need upgrading on the Vietnam side.

One of the planned high-speed lines would run from Vietnam's port cities of Hai Phong and Quang Ninh through Hanoi to Lao Cai province, which borders China's Yunnan province, the ministry said in a statement released late on Tuesday.

The other would run from Hanoi to Lang Son province, which borders China's Guangxi region, passing through an area densely populated with global manufacturing facilities, including some owned by Chinese investors.

The ministry didn't provide further details about the projects.

Earlier this month, Vietnam said it was seeking to learn from China to develop its first high-speed railway network and had sent its officials to work with Chinese railway companies.

A massive high-speed railway line linking capital Hanoi with business hub Ho Chi Minh City is also being planned in the country.

Vietnam's National Assembly chairman Vuong Dinh Hue met executives of Chinese railway companies on Monday during his ongoing visit to Beijing, where he was hosted by Xi Jinping.

This came after Vietnam and China signed dozens of cooperation agreements, including on railways, during a visit to Hanoi by Chinese President Xi Jinping in December.

Trade between Vietnam and China in the first quarter of this year rose 22% from a year earlier to $43.6 billion, according to Vietnamese government data.