To build the Cam Lo – La Son section, 125,000 square meters of forests belonging to the Forest Science Center for North of Central Vietnam between Quang Tri and Thua Thien Hue Provinces would need to be removed.

But Pham Xuan Dinh, the center's director, said it would take at least three months to finish 11 science projects being conducted in the forest. More than VND900 milion ($39,000) has been poured into the projects the past several years, Dinh said.

Construction managers have not been able to reach agreement on monetary and land compensation with the center.

Quang Tri Province leaders have urged the government to assist with the site clearance.

Work on the 98-kilometer Cam Lo - La Son section began in September last year at an estimated cost of VND7.7 trillion ($331 million).

It is the first of 11 sections to be built into the North-South Expressway, which is estimated to cost a total of VND118.72 trillion ($5.11 billion), including VND55 trillion ($2.37 billion) from state budget.