China's military is staging live-firing exercises in the country's west as part of a series of drills involving more than 140,000 troops, state media reported Tuesday.

The "Joint Action-2015D" exercises in the Chengdu Military Region are the first of five such drills involving units from the army, navy, air force, missile corps and other branches of the armed forces, the Xinhua News Agency said.

The drills are the latest in about 100 joint exercises planned for this year. They began last month but moved into the live-firing stage on Monday, Xinhua said.

The 2.3 million-member People's Liberation Army has stepped-up both the rigor and frequency of training as it emphasizes more realistic scenarios for fighting and winning battles around China's periphery. New stress has been placed on exercises integrating different branches of the armed forces, with a special command on joint exercises set up last year.

That includes recent live-firing exercises in the South China Sea, where China is involved in sharpening territorial disputes with five others and has embarked on a massive program of creating islands out of shoals and reefs that could operate as military outposts.

An exercise last month also included an assault on a mock-up of the presidential building in Taiwan, the self-governing island republic that China claims as its own territory and has vowed to bring to heel by military force if necessary.

Taiwan's Defense Ministry protested the training exercise, which was broadcast on the PLA's television channel, prompting a Chinese military spokesman to deny that the drill targeted any specific parties.