China fired multiple missiles around Taiwan on Thursday as it launched unprecedented military drills a day after a visit by US House of Representatives Speaker Nancy Pelosi to the self-ruled island that Beijing regards as its sovereign territory.

Asked about China's drills, Kremlin spokesman Dmitry Peskov said: "This is China's sovereign right."

"The tension in the region and around Taiwan was provoked... by the visit of Nancy Pelosi," Peskov told reporters on a conference call, as quoted by Reuters. "It was an absolutely unnecessary visit and an unnecessary provocation."

Meanwhile, Southeast Asian foreign ministers urged restraint Thursday as China launched massive military drills off Taiwan, warning the situation risked spiralling into "open conflicts".

A furious Beijing kicked off its biggest-ever exercises around Taiwan in response to US House Speaker Nancy Pelosi's visit this week to the self-ruled island.

Ministers from the 10-member Association of Southeast Asian Nations (ASEAN) meeting in Phnom Penh warned against "provocative action", AFP reported.

The situation "could lead to miscalculation, serious confrontation, open conflicts and unpredictable consequences among major powers", the ministers said in a joint statement published Thursday.

Chinese Foreign Minister Wang Yi is attending the talks along with his US counterpart Antony Blinken, though they are not expected to hold a one-on-one meeting.

At a meeting with ASEAN ministers, Blinken said the United States had contacted China "at every level of government" in recent days to call for calm and stability.

"I hope very much that Beijing will not manufacture a crisis or seek a pretext to increase its aggressive military activity," Blinken said.

"We and countries around the world believe that escalation serves no one and could have unintended consequences that serve no one's interests including ASEAN members and including China."