China's foreign ministry on Saturday condemned Prime Minister Narendra Modi's visit to Arunachal Pradesh, saying it "resolutely opposes" activities by Indian leaders in the region.

Modi's visit was part of a series of public meetings in the region aimed at garnering support for his Hindu nationalist Bharatiya Janata Party ahead of elections due by May.

Despite recent efforts to improve bilateral ties in both countries, disputes over the mountainous Indo-China border - which triggered a war in 1962 - and the region that China claims as southern Tibet have remained a sensitive issue.

"China urges the Indian side to proceed from the overall situation of bilateral relations, respect China's interests and concerns, cherish the momentum of improving relations between the two countries, and refrain from any actions that intensify disputes and complicate the border issue," its foreign ministry said in a statement.

In response, the official spokesperson at India's foreign ministry said in a statement that Arunachal Pradesh was "an integral and inalienable part of India".

"Indian leaders visit Arunachal Pradesh from time to time, as they visit other parts of India. This consistent position has been conveyed to the Chinese side on several occasions."

Both India and China have sought to rebuild trust after an armed standoff over a stretch of the Himalayan border in 2017.

Modi and Chinese President Xi Jinping met a number of times last year to give impetus to trade discussions. But progress, according to Indian government officials and representatives of various Indian trade bodies, has been very slow.