US spy planes deployed to Russia and Taiwan as Putin and Xi hold massive war games fuelling WW3 fears

US spy planes have been deployed to Russian and Taiwan as Vladimir Putin and Xi Jinping’s forces stage war games.

The RC-135 aircraft have monitoring massive missile firing drills in the Black Sea and a sizable Chinese air force incursion into Taiwan’s airspace.

Russia's navy practised firing at targets in the Black Sea off the coast of annexed Crimea using its Bastion coastal missile defence system, an advanced mobile anti-ship and surface-to-surface defence system.

A radar app showed a pair US Air Force RC-135 flying across the Black Sea and then round off the coast of the Crimea.

The drill came as Ukraine held joint military exercises with the United States, which are set to run until the end of the month.

Vladimir Putin's forces were shown carrying out strikes with truck-mounted missiles in video footage released by the Defence Ministry.

Crews fired from concealed positions and used drones to track a simulated enemy group of ships, it said.

Russia annexed the Crimean peninsula from Ukraine in 2014 and backed pro-Russian separatists in Ukraine's Donbass region.

The seven-year conflict with separatists has killed more than 13,000 people.

Meanwhile, Taiwan's air force scrambled on Thursday to warn off the Chinese aircraft which entered its air defence zone, its defence ministry said.

The incursion came as China voiced opposition on Thursday to Taiwan joining a major trans-Pacific trade deal.

The 24 Chinese aircraft included 12 J-16 fighters and two nuclear-capable H-6 bombers, the ministry said.

The US also sent an RC-135 close to the route the Chinese warplanes took to and from Taiwan's air defence identification zone (ADIZ).

It comes just days after China flew 10 fighter jets into Taiwan airspace after sending planes over 15 times in two weeks.

Beijing has sent different aircrafts including fighter jets, spotter planes and bombers into Taiwan's ADIZ every day this month, except for September 2.

China regards Taiwan as part of its territory and has long threatened to use force to bring it under its control.

"We firmly oppose any country having official exchanges with Taiwan and firmly oppose the Taiwan region's accession to any official treaties or organisations," said Chinese foreign ministry spokesman Zhao Lijian told reporters.

Taiwan responded by saying China has no right to decide who can join the trade pact given it is not itself yet a member.

'CHINESE BULLY'

"The Chinese government, with its deeds of just wanting to bully Taiwan in the international community, is the culprit for heightened cross-strait hostilities," Taipei's foreign ministry said in a statement.

China often sends military aircraft into Taiwan's air defence zone to display displeasure but Thursday's incursion was the biggest since June 15.

Negotiations for the sweeping trade deal were initially led by the United States as a way to increase its influence in the Asia-Pacific region.

China regards Taiwan as part of its territory and has long threatened to use force to bring it under its control.

Former Chinese president Chiang Kai-shek and his supporters fled to the island in 1949 following the Chinese Communist Party victory in the country's civil war.

The island of 25 million people has since developed its own democratic identity and party of current President Tsai Ing-wen supports moves towards full independence – which Beijing says will trigger war.