The United States (US) has expressed "serious concern" against China's conduct of military drills near Taiwan, saying it is an "unwarranted" provocation that risks escalation of tension in the Indo-Pacific region.

US Department of State spokesperson Matthew Miller said the People's Republic of China (PRC)'s actions may undermine peace and stability around the Taiwan Strait.

"The United States is seriously concerned by the People's Liberation Army joint military drills in the Taiwan Strait and around Taiwan," Miller said in a statement. "The PRC response with military provocations to a routine annual speech is unwarranted and risks escalation."

Taiwan's ministry said it had "dispatched appropriate forces to respond accordingly to protect freedom and democracy" and defended Taiwan's sovereignty.

The US urged China to refrain from further escalating the situation in the region.

"We call on the PRC to act with restraint and to avoid any further actions that may undermine peace and stability across the Taiwan Strait and in the broader region, which is essential to regional peace and prosperity and a matter of international concern," Miller said.  

Miller also noted that the US "remains committed" to its longstanding one-China policy, guided by the Taiwan Relations Act, the three Joint Communiqués, and the Six Assurances.

"We continue to monitor PRC activities and coordinate with allies and partners regarding our shared concerns," he added.

The Philippine military has a naval detachment on Mavulis Island in Itbayat, Batanes, which is 140 kilometers from Taiwan.

Meanwhile, the Department of National Defense has yet to comment on the recent security developments in Taiwan, particularly a possible breakout of war in the Taiwan Strait, which is just near the Philippine territory.