The Moon Jae-in administration of South Korea honors an "alliance decision" to deploy a high-profile US missile defense system here as it strives to enhance the transparency of relevant domestic procedures, a top defense official said Tuesday.

Vice Defense Minister Suh Choo-suk visited Seongju, where the US Forces Korea's THAAD battery is in partial operation.

Meeting with residents there, he pointed out that the THAAD deployment is an alliance decision aimed at countering North Korea's growing nuclear and missile threats, according to his ministry.

"He clearly delivered the government's position that it honors the decision and requested active cooperation from local residents," the ministry said.

Suh was also quoted as telling them that such illicit acts as the blockade of roads can never be justified.

Seongju, a traditionally tranquil town situated some 300 kilometers southeast of Seoul and known for melon farming, has become a venue for daily protest rallies since a private golf course there was picked as the site for the USFK's THAAD base in July last year.

Two interceptor launchers have been positioned there along with a powerful X-band radar and a fire control & communication system.

Four other launchers remain stored at a nearby US military base as the Moon administration is reviewing the scope of an environmental impact assessment of the site.

The liberal president, formerly a human rights lawyer, has taken issue with the speedy deployment of the THAAD system before his inauguration despite public controversy over whether it's a must to defend South Korea.

China has taken retaliatory economic measures against South Korea in protest of the THAAD deployment.

Moon believes there are "procedural problems" at home in reaching the deal with the US and implementing it.

The vice minister said his ministry will step up efforts for "communication" with the people to enhance procedural transparency and justification.

Suh inspected the THAAD base on June 11, four days after taking office. (Yonhap)