"We express strong dissatisfaction and opposition", said Zhang Shuili, a senior military official in China's western battle zone command, according to a Defence Ministry statement.
The ministry refuted the charge that the drone was flying into China's airspace.
Chinese state media has alleged that an Indian drone invaded its airspace and crashed "recently" without specifying when the incident took place. Russian Foreign Minister Sergey Lavrov will pay a visit to New Delhi on December 11 for talks with his Indian and Chinese counterparts Sushma Swaraj and Wang Yi, Russian Foreign Ministry Spokeswoman Maria Zakharova said on Wednesday.
The two countries saw relations worsen this summer when they became locked in a dispute over a Himalayan plateau. "We will fulfil our mission and responsibility and defend China's national sovereignty and security resolutely", he added. saying, without giving details about when or where the incident happened. "The matter is being dealt with in accordance with the established protocols through institutional mechanisms to deal with situations along the India- China border areas", the statement further read.
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.
The drone report comes months after the border stand-off near Doklam in Sikkim sector.
The standoff began in mid-June after Chinese troops started building a road on the remote Doklam plateau.
The diplomat added that the parties would discuss coordination of efforts within the UN, BRICS (that involves Brazil, Russia, India, China and South Africa), the Shanghai Cooperation Organization (SCO), the G20, the East Asia Summit (EAS) and the ASEAN Regional Security Forum.
In September, India's army chief General Bipin Rawat had said that India could not afford to be complacent and must be prepared for war.