Nancy Pelosi, the speaker of the United States House of Representatives, has visited Taiwan, despite warnings of severe consequences from China which claims the self-ruling island as its own.

Pelosi, second in line to the presidency, is the highest-profile elected US official to visit Taiwan in 25 years. Beijing has made clear that it regards her presence in Taiwan as a major provocation, setting the region on edge.

China’s military said it was on “high alert” and would “launch a series of targeted military actions in response” to the visit.

Taiwan said the trip displayed “rock solid” support from Washington.