North Korea has vowed to halt nuclear and missile tests if it holds talks with the US, in a major diplomatic breakthrough that could lead to a peaceful resolution of military tensions on the Korean peninsula.

The pledge was made during an unprecedented meeting between top South Korean security officials and the reclusive North Korean leader Kim Jong-un in Pyongyang, the North Korean capital, on Monday evening.

In another significant development, North and South Korea have agreed to hold their first joint summit in over a decade in late April, according to Chung Eui-yong, the leader of the South's two-day delegation to the North.

US President Donald Trump welcomed the move, talking up the chance of progress as he praised the "serious effort" being made by the three nations.

In a sign of softening rhetoric, Mr Trump tweeted on Tuesday morning: "Possible progress being made in talks with North Korea.

"For the first time in many years, a serious effort is being made by all parties concerned. The World is watching and waiting!"

However, Mr Trump added: "May be false hope, but the US is ready to go hard in either direction!"

The summit, between South Korean President Moon Jae-in and Kim Jong-un, will be held in the border village of Panmunjom, in the highly militarised zone between the two countries who are still technically at war.