China said it was conducting military exercises on Sunday off its coast opposite Taiwan after warning Speaker Nancy Pelosi of the US House of Representatives to scrap possible plans to visit the island democracy, which Beijing claims as part of its territory.

The ruling Communist Party’s military wing, the People’s Liberation Army, was conducting “live-fire exercises” near the Pingtan islands off Fujian province from 8am to 9pm (local time), the official Xinhua News Agency said. The Maritime Safety Administration warned ships to avoid the area.

Such exercises usually involve artillery. The one-sentence announcement gave no indication whether Sunday's exercise also might include missiles, fighter planes or other weapons.

Pelosi, who would be the highest-ranking American elected official to visit Taiwan since 1997, has yet to confirm whether she will go. President Xi Jinping warned his US counterpart, Joe Biden, in a phone call on Friday against “external interference” in Beijing’s dealings with the island.

China says Taiwan has no right to conduct foreign relations. It sees visits by American officials as encouragement for the island to make its decades-old de facto independence official.

The Ministry of Defence warned Washington this week not to allow Pelosi, who is Biden's equal in rank as leader of one of three branches of government, to visit Taiwan. A spokesman said the PLA would take unspecified “strong measures” to stop pro-independence activity.

The PLA has flown growing numbers of fighter planes and bombers near Taiwan and has in the past fired missiles into shipping lanes to the island.

Taiwan and China split in 1949 after a civil war that ended with a communist victory on the mainland.

The two governments say they are one country but disagree over which is entitled to national leadership. They have no official relations but are linked by billions of dollars in trade and investment.