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 defence this year has also angered Beijing, which claims the self-ruled island as its territory.

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

Taiwan's defence ministry said that they detected Chinese aircraft and ships around Taiwan on Monday morning, and have deployed their own forces and missile systems to monitor the situation. Its forces are on "high alert" to defend Taiwan and "protect our people", the ministry said.

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.

While some initial drills have begun, the military said it would conduct a major exercise from 08:00 to 18:00 local time on Tuesday.

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".

"Any sinister schemes to obstruct China's reunification are doomed to fail," the ministry's spokesman Lin Jian said at a regular press briefing on Monday.

While China has long called for the "peaceful reunification" with Taiwan, it also has a law stating it will resort to "non-peaceful means" to prevent the island's "secession".

Beijing has accused Taiwan's president Lai Ching-te of pursuing "Taiwan independence". The president maintains Taiwan is already a sovereign nation and therefore has no need to formally declare independence.

On Sunday, Lai said in a local television interview that Taiwan needed to "keep raising the difficulty so [China] can never meet the standard" for an invasion.

He also said that his administration was committed to "maintaining the status quo" and would not provoke China - though he added that peace relies on "real strength".

Polls consistently show that most Taiwanese people want the "status quo", meaning they neither want to unify with China, nor to formally declare independence.

Since 2022 Beijing has ramped up military drills in the Taiwan Strait, usually in response to what it deems as threats such as former US Speaker Nancy Pelosi's visit to Taiwan in 2022 and Lai's inauguration in 2024.

China's last live-fire exercise in the Taiwan Strait, held in April, simulated strikes on key ports and energy facilities, the People's Liberation Army said at the time. Along with the drills, the Chinese military released a series of cartoons depicting Lai as a "parasite".

This week's military drills are the first to be held under Yang Zhibin, the new chief of the Eastern Theater Command who assumed his role in October.

Taiwan holds military exercises of its own, both to prepare its population for an attack and showcase its defences to Beijing. This year's Han Kuang exercise, which took place over 10 days, was the largest and longest one yet.

Since taking office, Lai has vowed to boost defence spending and enhance the island's defence capabilities in the face of increasing tensions with Beijing.

In October, the Taiwanese president announced the building of a dome-like air defence system to guard against "hostile threats" - though he did not explicitly mention China.