Mainland coast guard patrols in waters East of Taiwan are lawful and necessary actions to safeguard China's territorial sovereignty and maritime rights, the Taiwan Affairs Office of the State Council said on Thursday.

The spokeswoman Zhu Fenglian made the remarks at a regular news conference in response to Taiwan leader Lai Ching-te's claim that recent mainland maritime operations were carried out "under the pretext of law enforcement and undermined regional peace and the rules-based international order".

Zhu stated that China has an exclusive economic zone and continental shelf in waters East of Taiwan Island. She criticized Japan and the Philippines for bypassing China and unilaterally launching maritime delimitation talks concerning relevant waters, which she claimed seriously violated international law and basic norms governing international relations, infringed upon China's maritime rights and interests, and are completely illegal and invalid.

ALSO READ: Mainland confirms rescue of Taiwan fishermen in East China Sea

The mainland coast guard's law enforcement patrols in the relevant waters are an exercise of jurisdiction in accordance with the law, Zhu said. She described the operations as a just move to safeguard national territorial sovereignty and maritime rights, as well as a necessary response to Japan and the Philippines bypassing China and infringing upon China's maritime rights.

"Our actions are reasonable, lawful, legitimate, and necessary," Zhu said, adding that they help safeguard the fundamental interests of the Chinese nation and the common interests of compatriots on both sides of the Taiwan Strait.

She said the patrols are also conducive to maintaining regional stability and maritime order and to protecting the lives and property of fishermen from both sides of the Strait.

Relevant countries should respect China's sovereignty, territorial integrity, and maritime rights, instead of confusing right and wrong, Zhu said.

READ MORE: Taiwan Affairs spokesperson warns against aggression toward mainland fisherman

She criticized the Democratic Progressive Party authorities for remaining silent over rights-infringing actions by Japan and the Philippines while ignoring damage to the interests of people on the island.

The DPP authorities have used the issue to spread separatist rhetoric advocating "Taiwan independence" and incite anti-mainland sentiment, Zhu said, adding that such actions make them accomplices of external forces harming the overall interests of the Chinese nation.

She said the DPP authorities have not only compromised with Japan and the Philippines but also echoed external forces' rights-infringing actions. Their attempt to seek independence by relying on external forces harms the overall interests of the Chinese nation and the immediate interests of Taiwan fishermen, she said.