North Korea has described high-level talks with a US delegation led by secretary of state Mike Pompeo as 'regrettable', as it accused Washington of trying to unilaterally pressure the country into abandoning its nuclear weapons.

Mr Pompeo had claimed the two days of talks with senior North Korean officials – though without leader Kim Jong Un – had resulted in commitments for new discussions on denuclearisation and the repatriation of the remains of American soldiers killed during the Korean War.

Before leaving Pyongyang, he said his conversations with senior North Korean official Kim Yong Chol had been 'productive,' conducted 'in good faith' and that 'a great deal of progress' had been made in some areas.

But the North provided a much harsher assessment of the talks, saying the US had betrayed the spirit of last month's summit between President Donald Trump and Kim Jong Un by making 'one-sided and robber-like' demands on 'CVID' – the complete, verifiable and irreversible denuclearisation of North Korea.

Secretary of State Mike Pompeo is pictured returning to a meeting with North Korea's Kim Yong Chol (not pictured). On Saturday, North Korea said the talks were 'regrettable'

The North said the outcome of the follow-up talks was 'very concerning' because it has led to a 'dangerous phase that might rattle our willingness for denuclearisation that had been firm'.

A spokesman for Pyongyang's Foreign Ministry said: 'We had expected that the US side would offer constructive measures that would help build trust based on the spirit of the leaders' summit… we were also thinking about providing reciprocal measures.

'However, the attitude and stance the United States showed in the first high-level meeting (between the countries) was no doubt regrettable.'

Mr Pompeo had said a Pentagon team would meet North Korean officials on or about July 12 at the border between North and South Korea to discuss the repatriation of remains, and that talks would be held soon on the destruction of North Korea's missile engine testing facility.

Mike Pompeo addresses the media before boarding his plane at Sunan International Airport in Pyongyang on Saturday. He said the meetings were 'productive'

In the days following his historic June 12 summit with Kim Jong Un in Singapore, Mr Trump had announced that the return of the remains and the destruction of the missile facility had been completed or were in progress.

Mr Pompeo said more talks are needed on both.

'We now have a meeting set up for July 12 – it could move by one day or two – where there will be discussions between the folks responsible for the repatriation of remains. (It) will take place at the border and that process will begin to develop over the days that follow,' he said as he boarded a plane for Tokyo.

On the destruction of the missile engine plant, he said: 'We talked about what the modalities would look like for the destruction of that facility as well, and some progress there as well, and then we have laid out a path for further negotiation at the working level so the two teams can get together and continue these discussions.'

Kim Yong Chol waved Pompeo goodbye at the airport on Saturday after their meetings

Earlier, Mr Pompeo and Kim Yong Chol both said they needed clarity on the parameters of an agreement to denuclearise the Korean peninsula that Mr Trump and Kim Jong Un agreed to in Singapore.

The trip was Mr Pompeo's third to Pyongyang since April and his first since the summit.

Unlike his previous visits, which have been one-day affairs during which he has met Kim Jong Un, Mr Pompeo spent the night at a government guesthouse in Pyongyang and did not see the North Korean leader, although US officials had suggested such a meeting was expected.