"We are monitoring PRC activities closely and coordinating with allies and partners regarding our shared concerns,"  US Department of State official spokesperson Matthew Miller said in a statement.

Miller urged Beijing to act with restraint.

"Using a normal, routine, and democratic transition as an excuse for military provocations risks escalation and erodes longstanding norms that for decades have maintained peace and stability across the Taiwan Strait, which is critical for regional and global security and prosperity and a matter of international concern," he said.

Miller said: " The United States remains committed to its longstanding one China policy, guided by the Taiwan Relations Act, the Three Joint Communiqués, and the Six Assurances."

The US issued the statement after China reportedly launched two days of military exercises around Taiwan.