President Park Geun-Hye on Tuesday evoked memories of her parents' assassination as she hit back at opposition to the planned deployment of an advanced US anti-missile system in South Korea.

The defence ministry announced last month that the Terminal High Altitude Area Defence system, or THAAD, will be installed in Seongju -- a rural county about 200 kilometres (135 miles) southeast of Seoul -- by the end of next year.

The decision was predicated on the growing threat posed by North Korea's advancing nuclear weapons and ballistic missile programme.

Protesting Seongju residents have alleged that the system's powerful radar poses health and environmental hazards, while opposition lawmakers have been less than supportive of the move.

At a cabinet meeting Park voiced frustration at the objections to what she insisted was an "unchangeable" decision to deploy the system.

"If we cannot take basic defensive steps like deploying THAAD, how can we protect the country and the people?" she said in remarks posted on her official website.

"I have lost my parents in the most excruciatingly painful way. My only remaining calling is to safeguard the country and people from various threats," she added.

Park's father, the former president and military strongman Park Chung-Hee, was shot dead by his own intelligence chief in 1979.

Her mother was killed in 1974 during an earlier assassination attempt on her father by a North Korean sympathiser.

Park Geun-Hye never married or had children and once proclaimed herself wedded to the nation and its welfare.

While promising to listen to the complaints of the Seongju residents, the president warned against listening to "strange and groundless rumours rather than scientific evidence" about the THAAD deployment.

"I ask the political circle to gather their wisdom and efforts to prevent internal division and conflict," she added.

Tensions on the divided Korean peninsula have been running high since Pyongyang carried out its fourth nuclear test in January, followed by a series of ballistic missile tests.

North Korea has threatened to take "physical action" against the THAAD deployment, saying any South Korean ports and airfields hosting US military "hardware" would become a target.