WASHINGTON, July 18 (FT) - Nancy Pelosi plans to visit Taiwan next month to show support for Taipei as it comes under mounting pressure from China, in what would be the first trip by a Speaker of the US House of Representatives to the country in 25 years.

Six people familiar with the situation said Pelosi would take a delegation to Taiwan in August. The 82-year-old California lawmaker cancelled a previous visit in April after she caught Covid-19.

Pelosi would be the most senior US lawmaker to visit the island since one of her predecessors as Speaker, Republican Newt Gingrich, travelled there in 1997.

Her visit will come as US-China relations remain mired in their worst state since the countries normalised diplomatic relations in 1979 and Washington switched diplomatic recognition from Taipei to Beijing.

In April, China’s foreign minister Wang Yi said a Pelosi visit would be a “malicious provocation”. News of the trip comes as US president Joe Biden and his Chinese counterpart Xi Jinping prepare to hold an online meeting in the coming weeks.

Three people familiar with the situation said the White House had expressed concern about the trip. The timing is sensitive for China because it will come in the same month as the August 1 anniversary of the founding of the People’s Liberation Army.