The offer was made by visiting Japanese Minister for Land, Infrastructure and Tourism Akihiro Ohta during his meeting with Road Transport and Highways Minister Nitin Gadkari here.
Ohta said his country, which has expertise in constructing roads in mountainous regions, can "actively contribute" in building such infrastructure in the Northeast.
"One of the issues that India is facing is the ageing of the road infrastructure. In that regard also I would particularly like to bring the topic of the northeastern road network improvement project.
"We have the technology of tunnel, also for reinforcement. We have also technology of making roads in very very narrow spaces. I think that is one area where Japan can very actively contribute.... Infact I understand that Japan International Cooperation Agency (JICA) is already carrying out a study from early this year," he said.
Noting that the new government is giving "highest priority" to building road network in the Northeast, Gadkari said "definitely the Japanese help, guidance and cooperation is very much useful".
The Japanese move comes weeks after Prime Minister Narendra Modi undertook a successful visit to the country where he sought help in improving India's infrastructure.
Infrastructure development in border areas has become a contentious issue in recent years between India and China. India is now focusing on such projects in a big way after a massive built-up by China in the region.
Japan has promised 3.5 trillion Yen (USD 35 billion or Rs 2,10,000 crore) to India through public and private funding over five years for various works, including building of infrastructure.