North Korean leader Kim Jong-un has agreed to meet South Korea's president next month and impose a moratorium on nuclear and missile tests if his country holds talks with the United States, a senior South Korean official said on Tuesday after returning from North Korea.

North Korean officials pledged not to use nuclear weapons on South Korea, according to the Blue House, South Korean's presidential palace.

"The North Korean side clearly stated its willingness to denuclearize," a statement from South Korean President Moon Jae-in's office said. "It made it clear that it would have no reason to keep nuclear weapons if the military threat to the North was eliminated and its security guaranteed."

The agreements, which follow a flurry of cooperative steps taken by the Koreas during last month's Pyeongchang Winter Olympics, brightened prospects for a dialogue between North Korea and the US over the North Korea's nuclear programme.

US President Donald Trump lauded possible talks between North and South Korea on Twitter 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!" Trump said.

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! May be false hope, but the U.S. is ready to go hard in either direction! — Donald J. Trump (@realDonaldTrump) March 6, 2018

In a press briefing on Tuesday, Moon's national security director Chung Eui-yong also announced that North and South Korean leaders will hold a landmark summit in April.

The summit of the two leaders will be held at the joint security area of Panmunjom, according to the official South Korean news agency, Yonhap.

The announcement followed high-level talks in Pyongyang between Chung and top North Korean leaders, including Kim Jong-un.

"The North side clearly affirmed its commitment to the denuclearisation of the Korean Peninsula and said it would have no reason to possess nuclear weapons should the safety of its regime be guaranteed and military threats against North Korea removed," he said.

Chung also said that North Korea has expressed willingness to hold "candid" talks with the US on the issues of denuclearisation and normalisation of bilateral ties.

He also said that as long as the there is progress in the talks between the US and North Korea, Pyongyang will pause its nuclear tests and ballistic missile launches.

The latest diplomatic development comes just weeks after South Korea's hosting of the Winter Games, in which athletes of the two Koreas marched together in a show of unity.

North Korea's official news agency also confirmed that the two states have reached a "satisfactory agreement".

It added that the North Korean leader has expressed his "firm will to vigorously advance" inter-Korean dialogue and the continued negotiations on reunification.