China on Saturday urged India not to aggravate problems on the border shared by the two nations, a day after the Indian president 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 Indian President Pranab 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 favorably 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.