North Korea threatened Monday that it will no longer engage with South Korea and will retaliate against Seoul for anti-Pyongyang "psychological warfare."

In a spokesman's statement, the North's powerful National Defense Commission said it will cut off military communication lines between the two Koreas and close its liaison office in the Mount Kumgang resort area.

"The army and people of the (North) will never deal with traitor Lee Myung-bak and his clan," the statement said, referring to the South Korean president by name.

The North "will take a physical action without any notice any time against any target to cope with the anti-DPRK psychological warfare," the statement said, referring to the North by the acronym of its official name, the Democratic People's Republic of Korea.

The announcement, carried by the North's official Korean Central News Agency, represents the latest escalation of tensions between the two Koreas.

The animosity between the two Koreas reached a peak when the North torpedoed a South Korean warship in March last year and shelled a southern border island eight months later.

(Yonhap)