China is holding military drills around Taiwan simulating the seizure and blockade of the island's key areas, as a warning against 'separatist forces'.

The army, navy, air force and rocket force have been dispatched for the drills which include live-fire exercises, the Chinese military said.

Codenamed 'Justice Mission 2025', the drills are taking place days after the US announced the sale of one of its largest weapons packages to Taiwan worth $11bn (£8.2bn). That move drew sharp protest from Beijing which in turn sanctioned US defence firms.

Taiwan's push to ramp up its defense this year has also angered Beijing, which claims the self-ruled island as its territory.

Taiwan's presidential office has criticized the upcoming Chinese drills, calling them a challenge to international norms.

Its defense ministry said it had detected 89 Chinese military aircraft and 28 warships and coastguard vessels near Taiwan on Monday.

The ministry said separately it had deployed its own missile systems and forces to monitor the situation, adding they are on 'high alert' to defend Taiwan and 'protect our people'.

In a post on Weibo, the Chinese military's Eastern Theater Command, in charge of the Taiwan Strait, described the upcoming military exercise as a 'shield of justice'.

'All those plotting independence will be annihilated upon encountering the shield!' the post read.

Beijing's foreign ministry called the drills a 'severe punishment for separatist forces seeking independence through force' and warned 'external forces' against 'using Taiwan to contain China'.

While Taiwan holds military exercises of its own to prepare for potential conflicts, China has ramped up its military presence in the Taiwan Strait in response to actions it views as provocations.

Both regions are on high alert, as military strategists analyze the implications of such drills on the delicate balance of power in Asia.