The UK on Wednesday summoned China's ambassador demanding he explain Beijing's "aggressive behaviour" and "escalation" of actions targeted at Taiwan in recent days.

Foreign Secretary Liz Truss, the favourite to become the UK's next prime minister, said she had called in ambassador Zheng Zeguang to explain Chinese missile launches and incursions into Taiwanese air space.

The military drills followed a visit by US House of Representatives speaker Nancy Pelosi to the island last week.

"The UK and partners have condemned in the strongest terms China's escalation in the region around Taiwan, as seen through our recent G7 statement," Truss said in a statement.

"I instructed officials to summon the Chinese ambassador to explain his country's actions.

"We have seen increasingly aggressive behaviour and rhetoric from Beijing in recent months, which threaten peace and stability in the region."

Relations between China and the UK have soured in recent years, particularly over London's condemnation of the treatment by Beijing of Muslim Uighurs and pro-democracy protests in Hong Kong.