"China believes the decision to stop nuclear tests and focus on developing the economy and improving people's living standards will help further ease the situation on the Korean peninsula and help to promote the process of denuclearisation and attempts to find a political settlement," Chinese foreign ministry spokesman Lu Kang said in a statement.

"China will support North Korea ... (to engage in) dialogue and consultation with the relevant parties."

The surprise announcement comes less than a week before the North Korean leader Kim Jong Un meets South Korean President Moon Jae-in for a summit in the Demilitarised Zone that divides the peninsula, ahead of an eagerly-awaited encounter with US President Donald Trump.

However, Kim gave no indication Pyongyang might be willing to give up its nuclear weapons, or the missiles with which it can reach the mainland United States.

For years, the impoverished North has pursued a "byungjin" policy of "simultaneous development" of both the military and the economy.

But the leader said that now North Korea was a powerful state, "the whole party and country" should concentrate on "socialist economic construction".