China said on Monday that its military “not sit idly by” if US House of Representatives Speaker Nancy Pelosi visits Taiwan.

The latest warning was issued during a Chinese foreign ministry regular briefing. Spokesperson Zhao Lijian also said that because of Pelosi’s status as the “No. 3 official of the US government”, a visit to Taiwan, which China claims as its own, would “lead to egregious political impact”.

Pelosi was set to kick-off a tour of four Asian countries on Monday in Singapore amid intense speculation that she may risk the wrath of Beijing by also visiting self-ruled Taiwan.