The department wants the bridge to become technically operational by the middle of this month.
The bridge is being constructed on National Highway 2, which runs through the two northern provinces of Vinh Phuc and Phu Tho.
The project was launched in November 2013 under a build-operate-transfer contract, with investment of more than VND1.9 trillion (US$90 million). It is a joint venture of CIENCO 1, Yen Khanh and Thai Son Companies, which were selected as the investors by the transport ministry.
Vice head of the department for transport construction and quality management Phan Quoc Hieu said 83 per cent of the construction work was completed by the end of last month, three per cent less than planned.
Hieu said the construction of the Kenh flyover, which is part of the project, was going slow as work on the flyover's surface was yet to start.
About 12,000 tonnes of cement was left on the construction site, making it difficult to have enough machines, equipment and staff, he said.
"The final stage, including the installation of banisters and barriers, require time and technique to ensure technical and artistic value," he said.
Hieu said the transport ministry has asked the investors, inspectors and constructors to mobilise more staff and equipment for the construction site.
They were also asked to work extra hours.
Official Hieu said the work quality must be ensured by all means.
"Any work found to be substandard will be stopped and the builders must fix it with their own funds," he said.
The new Viet Tri Bridge will be a four-lane bridge, with a speed limit of 80km per hour. The bridge and the approach roads have a total length of more than 3km.
The bridge is expected to help reduce traffic jams and meet the travel needs of people in Vinh Phuc, Phu Tho and other north-western provinces. It will also ease the rush during the Hung Kings' Temple Festival at the Hung Kings Temple Site in the northern province of Phu Tho.
