North Korean leader Kim Jong-un has said he will suspend all missile tests and shut down a nuclear test site with immediate effect.
"From 21 April, North Korea will stop nuclear tests and launches of intercontinental ballistic missiles," the Korean Central News Agency said.
The decision is aimed at pursuing economic growth and peace on the Korean peninsular, state media report.
Mr Kim is due to meet his South Korean counterpart Moon Jae-in next week.
He is also expected to hold an unprecedented summit with US President Donald Trump by June. If it takes place, it will be the first meeting between a sitting US president and a North Korean leader.
"This is very good news for North Korea and the World - big progress!," Mr Trump tweeted after Kim Jong-un's announcement.
On Thursday, the US leader said there was a "bright path available to North Korea when it achieves denuclearisation".
A spokesperson for the South Korean president called the North's move "meaningful progress".
"It will also contribute to creating a very positive environment for the success of the upcoming South-North summit and North-United States summit," a statement from President Moon Jae-in's office said.
North Korea has repeatedly defied international sanctions over its weapons programme.
In November, it said it had successfully tested a new type of intercontinental ballistic missile that could reach the whole of the continental United States.
The test drew swift international condemnation. UN Secretary General Antonio Guterres said Pyongyang had shown "complete disregard for the united view of the international community".
The latest announcement from Pyongyang comes during a thawing of relations between North and South Korea.
A telephone hotline has been set up between Mr Kim and Mr Moon ahead of the first inter-Korean summit in over a decade.
"It was as if we were talking to a neighbour right next door," a South Korean official told local media after a successful test call that lasted 4 minutes 17 seconds.
The agreement to set up the phone link was made last month when Mr Moon's top security adviser travelled to Pyongyang for a meeting with Mr Kim, who then agreed to hold the inter-Korean summit.
The two states remain technically at war since the 1950-53 Korean War ended in an armistice, with neither side able to claim an outright victory.