North Korea's top governing body has proposed high-level nuclear and security talks with the US in an appeal sent just days after calling off talks with South Korea.

The powerful National Defence Commission headed by the North Korean leader, Kim Jong-un, issued a statement on Sunday through state media proposing "senior-level" talks to ease tensions and discuss a peace treaty formally ending the Korean war.

There was no immediate response from Washington, but President Barack Obama's envoy on North Korea said on Friday that while the US was not averse to talking with Pyongyang, the bar for resuming engagement was higher in the wake of repeated nuclear threats and provocations.

Foreign analysts expressed scepticism, saying impoverished North Korea often called for talks after raising tensions with provocative behaviour in order to win outside concessions.

The rare proposal for talks between the Korean war foes follows months of acrimony over North Korea's defiant launch of a long-range rocket in December and a nuclear test in February. These were considered provocative acts, which drew tightened UN and US sanctions. The US and South Korea countered the moves by stepping up annual springtime military exercises that prompted North Korea to warn of a "nuclear war" on the Korean peninsula.

However, as tensions subsided in May and June, Pyongyang made tentative overtures to re-establish dialogue with South Korea and Washington.

In a notable shift in propaganda in Pyongyang, posters and billboards calling on North Koreans to "wipe away the American imperialist aggressors" have been taken down in recent weeks.

Meanwhile, a recent proposal from Pyongyang for cabinet-level talks with South Korea – the first in six years – led to plans for two days of meetings in Seoul earlier this week. The talks fell apart even before they had begun, amid bickering over who would lead the two delegations.