TAIPEI – United States House Speaker Kevin McCarthy will host a meeting in California on Wednesday with Taiwans President Tsai Ing-wen, part of a sensitive US stopover that has drawn Chinese threats of retaliation.

Here are the key issues in Taiwan-US, China-US and Taiwan-China relations, why China is so angry about the meeting and what it might do to express its anger: Why is China so angry?

Taiwan is a deeply emotive issue for Chinas ruling Communist Party, and for Chinese President Xi Jinping.

The Peoples Republic of China has claimed Taiwan as its territory since the defeated Republic of China government fled to the island in 1949 after losing a civil war with former Chinese leader Mao Zedongs communists.

China has repeatedly called on US officials not to engage with Taiwanese leaders, viewing it as support for Taiwans desire to be viewed as separate from China.

China has never renounced the use of force to bring democratically governed Taiwan under its control, and in 2005 passed a law giving Beijing the legal basis for military action against Taiwan if it secedes or seems about to. How will China react to the meeting?

China staged war games around Taiwan last August after then House Speaker Nancy Pelosi visited Taipei, and has threatened unspecified retaliation if the McCarthy meeting goes ahead.

While Taiwanese and US officials have said in the run-up to the McCarthy-Tsai meeting that they have not seen any unusual activity from Chinas military, Taiwan is also on alert for any further Chinese drills.

Taiwanese and US officials have also said that by staging the meeting outside of Taiwan, it may help tone down Chinas reaction.

Over the past three years or so, Chinas air force has flown almost daily into the skies near Taiwan, in which Taiwan calls grey zone warfare designed to test and wear out its forces.

While Chinas air force has never flown into Taiwans territorial airspace, it fired missiles high over the island after Mrs Pelosis visit. More On This Topic US House Speaker Kevin McCarthy to meet Taiwanese President Tsai Ing-wen in California China warns US House Speaker McCarthy against meeting Taiwan President Tsai What is the relationship between Taiwan and the US?

In 1979, the US severed official relations with the government in Taipei and instead recognised the government in Beijing. A Taiwan-US defence treaty was terminated at the same time.

Post-1979, the US relationship with Taiwan has been governed by the Taiwan Relations Act, which gives a legal basis to provide Taiwan with the means to defend itself, but does not mandate that the US come to Taiwans aid if attacked.

While the US has long followed a policy of strategic ambiguity on whether it would intervene militarily to protect Taiwan in the event of a Chinese attack, US President Joe Biden has said he would be willing to use force to defend Taiwan.

The US continues to be Taiwans most important international source of weapons, and Taiwans contested status is a constant source of friction between Beijing and Washington. What is Taiwans position and diplomatic status?

Taiwans government says that as the Peoples Republic of China has never ruled the island, it has no right to claim sovereignty over it or speak for or represent it on the world stage, and that only Taiwans people can decide their future.

Taiwans official name continues to be the Republic of China, though these days the government often stylises it as the Republic of China (Taiwan).

Only 13 countries now formally recognise Taiwan, after Honduras ended ties in March.

Taiwans government says that as the Republic of China is a sovereign country, it has a right to state-to-state ties. More On This Topic After contentious US visit, Taiwans president arrives in Central America China stages combat patrols after warning against Tsai-McCarthy meeting What are relations like between Taipei and Beijing?

In one word bad.

China views Ms Tsai as a separatist and has rebuffed repeated calls from her for talks. Ms Tsai says she wants peace, but that her government will defend Taiwan if it is attacked.

She says the Republic of China and Peoples Republic of China are not subordinate to each other. Beijing says Ms Tsai must accept that both China and Taiwan are part of one-China. REUTERS More On This Topic US says China cant alter routine trip by Taiwan President Taiwan says 10 Chinese aircraft crossed Taiwan Strait median line Your browser does not support iframes, but you can use the following link: Link