China has expressed strong dissatisfaction to India over Indian Prime Minister Narendra Modi's attendance at a tunnel inauguration in the eastern sector of the China-India border, saying that India has no right to develop China's Zangnan, or the southern part of the Xizang autonomous region.

"Zangnan is China's territory. The Chinese government never recognizes, and resolutely opposes the so-called Arunachal Pradesh illegally set up by India," China's Foreign Ministry spokesman Wang Wenbin said on Monday.

Indian reports said Modi inaugurated the "strategically significant "Sela Tunnel in "Arunachal Pradesh "on Saturday.

Voicing China's strong dissatisfaction and firm opposition to Modi's move, Wang said the border issue between the two countries is not yet resolved.

"The relevant move will only complicate the issue and impose a negative influence on the situation in the border area," Wang said.

The inauguration came less than three weeks after China and India held the 21st round of commander-level talks over border issues.

During the talks, both sides agreed to keep up communications through military and diplomatic channels, and work for a resolution accepted by both sides as soon as possible, so that the situation in the border area will improve.