Metro Manila (CNN Philippines, April 11) — China has the "natural right" to station troops and deploy defense facilities in the Spratly Islands, their defense ministry said Wednesday, amid critics' allegations that Beijing is militarizing contested features in the South China Sea.

In a statement posted on the Ministry of Defense's website, Ministry Spokesperson Senior Colonel Ren Guoqiang said the Nansha Islands — the Chinese name for the Spratly group of islands — are part of Chinese territory.

"The Nansha Islands are China's territory," Ren's statement read. "It is the natural right of a sovereign state for China to station troops and deploy necessary territory defense facilities on the relevant islands and reefs of the Nansha Islands."

The comment comes after a show of force by a Chinese aircraft carrier and other sea vessels in the South China Sea, and reports from the Wall Street Journal that China has installed military jammers on the islands.

The Defense Ministry spokesperson said China will pursue a national defense policy that is "defensive in nature" and a military strategy of "active defense."

"It is conducive to safeguarding the state's sovereignty and security, ensuring the freedom and security of navigation channels in the South China Sea, and maintaining regional peace and stability," Ren said.

"It is not directed against any country," he added.

Malacañang earlier said the presence of Chinese vessels in the disputed waters is not a cause for concern.

Critics have called out the construction of Chinese air and naval base structures on the Spratly's Islands,saying it is China's way of militarizing the contested waters.

READ: Vertical structures built on reefs in S. China Sea - Inquirer reporter

The eastern giant has asserted ownership of majority of the South China Sea, with other claimant countries — including the Philippines — disputing China's territorial claims. But the Duterte administration has since seen warmer ties with China, with President Rodrigo Duterte himself repeatedly saying the Philippines cannot afford to go to war with China over the maritime row.