China has started mobilizing military forces around the Korean peninsula in response to rising tensions that follow recent threats by North Korea to launch missile attacks against its southern neighbor and the United States.

China has started mobilizing military forces around the Korean peninsula in response to rising tensions that follow recent threats by North Korea to launch missile attacks against its southern neighbor and the United States.

According to US officials, Pyongyang’s declaration of a ‘state of war’ against South Korea has led to the Chinese People’s Liberation Army (PLA) to increase its military presence on the border with the North. The officials say the process has been going on since mid-March, and includes troop movements and readying fighter jets. The PLA is now at ‘Level One’ readiness, its highest.

Chinese forces, including tanks and armored personnel carriers, have been spotted in the city of Ji’an and near the Yalu River, which splits China and North Korea. Other border regions were also reportedly being patrolled by planes.

China has also been conducting live-firing naval exercises in the Yellow Sea, scheduled to end on Monday. The move is widely viewed as open support for North Korea, which continues to show extreme opposition to the US-South Korean military drills that are to last until May.

The news comes as the US deployed its USS Fitzgerald destroyer off the coast of North Korea, adding to its Sunday deployment of F-22 fighter jets to take part in the drills with the friendly South, which has further served to heighten tensions on the peninsula.

Meanwhile, North Korea has been mobilizing its short and medium-range missile arsenal, according to analyses of satellite imagery. Officials say Pyongyang is set to test its new KN-08 medium-range mobile missile; they say preparations have been spotted in the past. Pyongyang claims that since March 26, its forces have been placed on their highest possible status of alert.

Although officials believe Pyongyang will not provoke Seoul during the war games, they also fear that a miscalculation by South Korea could lead to all-out war, following its promise of retaliation against the North, should it launch its missiles first.