China on Saturday urged India not to aggravate problems on the border shared by the two nations, a day after President Pranab Mukherjee toured a disputed region and called it an integral part of the country.
The two countries, which fought a brief border war in 1962, only last month signed a pact to ensure that differences on the border do not spark a confrontation.
But Mukherjee's visit to the state of Arunachal Pradesh in the remote eastern stretch of the Himalayas that China claims as its own provoked a fresh exchange of words.
"We hope that India will proceed along with China, protecting our broad relationship, and will not take any measures that could complicate the problem, and together we can protect peace and security in the border regions," China's official news agency, Xinhua, quoted Qin Gang, a spokesman of the country's ministry of foreign affairs, as saying.
"Currently Sino-India relations are developing favourably and both sides are going through special envoy meetings and amicable discussions to resolve the border dispute between our two countries."
Mukherjee was on a routine visit to Arunachal which has been part of the Indian state for decades, and where India has regularly been holding elections. But China has of late grown increasingly assertive and questioned New Delhi's claims over the territory, calling it instead South Tibet.
Mukherjee told members of the state's legislative assembly it was "a core stakeholder in India's Look East foreign policy" that intends to link the country's northeast with South East Asia.
"We seek to make our neighbours partners in our development," Mukherjee said in Itanagar, the state capital. "We believe that India's future and our own best economic interests are served by closer integration with Asia."
China lays claim to more than 90,000 sq km (35,000 sq miles) disputed by New Delhi in the eastern sector of the Himalayas, while India says China occupies 38,000 square km of its territory on the Aksai Chin plateau in the west.