North Korea has threatened to cancel a much-anticipated and unprecedented summit between its leader Kim Jong-un and US President Donald Trump.

It has also cancelled high-level talks with South Korea due for tomorrow over the Max Thunder joint military exercises between the US and the South.

Tomorrow’s meeting was due to focus on plans to implement a declaration that emerged from a inter-Korea summit on 27 April, including promises to formally end the Korean War and pursue "complete denuclearisation".

North Korea's official Korean Central News Agency called joint US-South Korean military exercises a "provocation" and said Pyongyang had no choice but to suspend the talks.

The meeting would have been the latest in a series of actions taken by North Korea that have spurred hopes that the seven-decade conflict on the Korean Peninsula may be coming to an end.

The White House has said that it is aware of reports that the meeting has been cancelled.

In a statement, White House spokeswoman Sarah Sanders said: "The United States will look at what North Korea has said independently, and continue to coordinate closely with our allies,"

North Korea has scheduled the dismantlement of its nuclear bomb test site for sometime between 23-25 May in order to uphold its pledge to discontinue nuclear tests, the country's state media reported on Saturday, a month ahead of a planned North Korea-US summit in Singapore.

Mr Trump and Mr Kim will meet on 12 June, a scenario that seemed improbable given the insults and threats exchanged between the two leaders in the past year.

The US State Department said tonight that it is operating under the notion that the summit between President Trump and Kim Jong-un will proceed as expected.

It said planning for the summit is ongoing.

Meanwhile, a US monitoring group has said satellite photos indicate North Korea has begun dismantling its nuclear test site.

In a move welcomed by Washington and Seoul, North Korea said at the weekend it will "completely" destroy the Punggye-ri test site.

Punggye-ri, in the northeast of the country, has been the site of all six of the North's nuclear tests, the latest and by far the most powerful in September last year, which Pyongyang said was an H-bomb.

North Korea pledged to destroy the testing ground after Mr Kim last month declared the country's nuclear force complete and said it had no further need for the complex.

Several key operational buildings, as well as smaller sheds, had been razed and rails connecting the tunnels to their waste piles were removed, the monitoring group said.

The US is seeking the "complete, verifiable and irreversible denuclearisation" of North Korea and stresses that verification will be key.

Sceptics warn that North Korea has yet to make any public commitment to give up its arsenal, which includes missiles capable of reaching the United States.