South Korea blames the North for two deadly attacks against it last year that killed 50 people and dismissed Monday’s warnings as part of a North Korean pattern of making threats and then easing tensions in order to wrest concessions from Seoul and other nations.

North Korea has appealed for food aid this year, and leader Kim Jong Il in late April reportedly proposed summit talks with South Korean President Lee Myung-bak.

On Monday, however, North Korea said it will no longer deal with South Korea, accusing Seoul of worsening animosity by holding firing drills near the border and aiming propaganda at the North.

“The moves of the Lee Myung-bak group of traitors to escalate confrontation with (North Korea) have reached an extreme phase,” the North’s powerful National Defense Commission said in a statement carried by the official Korean Central News Agency.

The statement renewed a warning that the North will take unspecified “physical actions” against the South over its propaganda campaign, which includes radio broadcasts.

North Korea also said it planned to cut off communications along the countries’ eastern border and shut down a liaison office in a now-stalled joint tourism facility in the North. The statement, however, doesn’t mention other military and nonmilitary hotlines across the border.

South Korea quickly downplayed the North’s warning. “North Korea has often said it wants talks while applying pressure on us at the same time. We see (the latest threat) as part of such an offensive,” Unification Ministry spokeswoman Lee Jong-joo said.

The two Koreas are still technically at war because their 1950-53 conflict ended with an armistice, not a peace treaty.