"I apologize again for not informing you prior to the announcement," Hwang told the county's residents. His address was broadcast live on CNN affiliate YTN.

Hwang tried to assure the residents that THAAD was safe, saying "if this harms your safety by even just a little bit, our government cannot deploy this. No, we won't deploy this."

But the protesters weren't satisfied. YTN broadcast video of protesters throwing eggs and water bottles at Hwang, which stained the Prime Minister's suit. His aides and security guards tried to block the flying objects with umbrellas and their bare hands.

Hwang was later stranded in his vehicle for six hours after angry protesters and a tractor surrounded his convoy, according to YTN.

Tensions rising

Tension in the Korean peninsula escalated to a new high earlier this year, after North Korea conducted its fourth nuclear test and fired a long-range rocket, which South Korea called a long-range missile test.

The U.S. and South Korea announced in February they were formally discussing deploying THAAD and said last week it would place it in South Korea.

North Korea responded to the THAAD announcement with new threats on Thursday. The country's state-run news agency KCNA published an article that said Pyongyang would strengthen its nuclear force and its "merciless sword of justice will cut off (South Korean President) Park Geun-hye's windpipe... despite her attempt to cling (to the) coattails of foreign forces."