The new project has been given an official nod by India's Department of Economic Affairs with 50 percent funding from the Asian Development Bank (ADB), officials told IANS, adding that the road project will cover West Bengal and Manipur on the Indian side, as of now.

"The mandate is for completing the project within the next two years," a senior official said.

"The primary idea behind the Bangladesh-Bhutan-India-Nepal (BBIN) road initiative is to improve ground connectivity in the region," said Leena Nandan, Joint Secretary, Ministry of Road Transport and Highways.

"We have taken up five highway stretches in the country, which are very important for such a connectivity to succeed. This project is entirely different and new -- and about to be rolled out," Nandan told IANS.

The project -- as per a list accessed by IANS -- includes, among others, an upgrade of the 122-km Siliguri-Mirik-Darjeeling ($15 million) and the widening of the 60-km National Highway-35 (Kolkata-Bangaon) on the border with Bangladesh ($130 million).

It also includes a new 123-km road to connect with Diamond harbour, on the outskirts of Kolkata, at a cost of $250 million. All these are in West Bengal and will be entrusted to the state's Public Works Department for execution, officials said.

"This apart, two highways are going to come up in Manipur -- 115-km Ukhrul-Tolloi-Tadubi ($230 million) and a 138-km split, four-lane road between the Kohima-Kedima Kring-Imphal section of National Highway-39 ($280 million)," said AD James, Deputy Secretary at the Ministry of Road Transport and Highways.

"These two roads are to be executed by the National Highway Infrastructure Development Corp. They are currently in the DPR (detailed project report) stage," James told IANS. Officials are also looking at the possibility of shorter routes.

Apart from the works under the $1 billion project, a 600 metre bridge and a 110 km-road in the Impal-Moreh stretch of Manipur are also being planned under the broader BBIN road initiative. The Manila-based bank has agreed to fund up to 50 percent of this project as well, officials said. The DPR for this is ready. Clearances are awaited from Nepal.

"This bridge will connect Kakarbhitta in Nepal with Panitanki in West Bengal. Once we receive the necessary approvals, we would like to bid for the projects as early as possible, say by November-end," said Anand Kumar, Managing Director, National Highways and Infrastructure Development Corp.

The four South Asian nations, led by Road Transport and Highways Minister Nitin Gadkari from the Indian side, had signed a landmark Motor Vehicles Agreement in June last year in the Bhutan capital Thimpu to regulate passenger, personnel and cargo vehicular traffic among the South Asian neighbours.

"This agreement between sub-grouping of four South Asian nations -- Bangladesh, Bhutan, India and Nepal -- will pave the way for seamless movement of people and goods across their borders for the benefit and integration of the region and its economic development," Gadkari had said.

A joint statement later said: "Taking note of the finding that transforming transport corridors into economic corridors could potentially increase intra-regional trade within South Asia by almost 60 percent, and with the rest of the world by over 30 per cent."

As regards the funding, James said talks were simultaneously on with ADB to look beyond the committed 50 per cent. "There are chances that the bank may even fund up to 72 per cent of the total cost for the project. Then we will get around $700 million."