North Korea warned South Korea on Thursday that failure to cancel an upcoming military drill with the United States would push the two sides "to the brink of war".

In a lengthy statement that offered no direct response to Seoul's recent offer of high-level talks, the Committee for the Peaceful Reunification of Korea (CPRK), which handles cross-border ties, issued a long list of measures the South should implement if it was "sincere" about improving relations.

The joint military drill scheduled to begin Monday "should be cancelled unconditionally", the statement said, adding that failure to do so would push the "Korean peninsula to the brink of a war and increase the danger of a nuclear war".

The annual Ulchi-Freedom Guardian exercise, aimed at testing combat readiness for a North Korean invasion, is scheduled to begin August 18.

Although largely played out on computers, it involves tens of thousands of South Korean and US troops.

Pyongyang's anger over the drill is likely to prompt some extended sabre rattling during the visit to South Korea of Pope Francis, who arrives in Seoul Thursday for five days.

The pope is due to conduct a special inter-Korean "reconciliation" mass on the same day that the Ulchi Freedom exercise begins.

"US domination and interference should be terminated on the Korean peninsula," the CPRK said, demanding the withdrawal of all US forces from South Korea.

The statement was carried by the North's official KCNA news agency ahead of the 69th anniversary Friday of the Korean peninsula's liberation from Japanese rule.

Earlier this week, South Korea had proposed a fresh round of high-level talks with the North to discuss another possible reunion for families separated by the 1950-53 Korean War.

But the CPRK offered no direct response, though it noted that the South Korean authorities should demonstrate their desire for improved ties "through their practical actions, not talking only".

Seoul's Unification Ministry, which handles cross-border affairs on the South side, had proposed a meeting at the border truce village of Panmunjom on August 19.

An earlier round of talks in February had marked the highest-level official contact between the two Koreas for seven years, and led to a family reunion later the same month.

But since then tensions have escalated, with the North conducting an extended series of missile tests after the South pushed ahead with other joint military drills involving US forces.