While India and Bhutan said that it violated the status quo along the India-Bhutan-China worldwide trijunction, Beijing claimed that it was China's territory.
India and China were recently locked in a standoff in the Dokalam after Chinese troops began constructing a road near the Bhutan trijunction.
After Chinese state media alleged that an Indian drone "invaded" their airspace, the Defence Ministry said the unmanned aerial vehicle (UAV) had crashed into Chinese territory due to some technical problem. "We strongly express our dissatisfaction and opposition", deputy director of the army's western theatre combat bureau, Zhang Shuili, said in a statement.
He did not provide the exact location of the crash.
Chinese military's western theatre command jurisdiction covers nearly all of the 3488-km LAC, including Tibet's border region with India and the Ladakh region.
"China's border defence forces took a professional and responsible attitude in conducting an inspection of the device", Zhang said, adding that the military would "resolutely defend" China's sovereignty and security.
The 15th RIC meeting will be held in New Delhi India on December 11.
The Indian border security personnel immediately alerted their Chinese counterparts over the missing UAV, it said.
New Delhi and Beijing eventually agreed to pull back their troops towards the end of August ahead of Prime Minister Narendra Modi's visit to China for the G20 Summit. India, citing concerns about territorial integrity, moved soldiers into the flashpoint zone to halt the work, prompting Beijing to accuse it of trespassing.
This will be the first visit by a top Chinese official to India after the Dokalam crisis and commencement of second five-year term after Chinese President Xi Jinping. The road was being built by the Chinese troops in the area also claimed by Bhutan.