China's claim on Arunachal Pradesh was taken up with Beijing by New Delhi, which conveyed its disappointment and concern over Chinese envoy Sun Yuxi's statement in this regard.
This was disclosed in a communication dated January 16 from the external affairs ministry to Kiren Rijiju, the Bharatiya Janata Party member of Parliament from Arunachal Pradesh, in reply to his letter to the prime minister on November 20.
Sun's claim was also rejected by External Affairs Minister Pranab Mukherjee.
The letter to Rijiju from Joint Secretary Ashok K Kantha in the external affairs ministry said Mukherjee had earlier unambiguously rejected the Chinese contention and stated that Arunachal Pradesh was an integral part of India.
He had addressed the issue in Parliament on November 24, and in a suo moto statement in the House four days later.
The letter said the Indian government was fully vigilant about the need to safeguard the country's territorial integrity and vital national interests. "Appropriate steps are taken for the management of the borders."
Infrastructure development, including road connectivity in border areas, was being given special attention both from the perspective of taking the benefits of development to local people and for improving the management of borders, it said.
Several road schemes have been undertaken in Arunachal Pradesh, it added.