China has summoned India's ambassador over Prime Minister Narendra Modi's visit to the northeastern Indian state of Arunachal Pradesh in the disputed border region in the Himalayas.
The Chinese Foreign Ministry said on Saturday that Vice Foreign Minister Liu Zhenmin had called in Indian Ambassador Ashok Kantha to express "strong dissatisfaction and firm opposition" to the visit, saying it undermined China's territorial sovereignty.
Liu said China places importance on developing relations with India.
It called for New Delhi not to take any action that may complicate the issue and stick to resolving it through bilateral negotiations.
Modi on Friday visited the northeastern Indian state of Arunachal Pradesh, an immense territory of nearly 84,000 square km that China claims as part of its Tibet region.
Modi marked the 28th anniversary of Arunachal Pradesh being declared a state, opened a train line and called for hydropower projects to spur regional growth.
China and India fought a brief but bloody frontier war in 1962.
They agreed to a line of actual control in 1996 and began talks on settling the dispute.
While analysts see little danger of a conventional war over the border, frequent skirmishes make it difficult to achieve a lasting resolution.