Mike Pompeo, currently the director of the CIA and President Donald Trump's pick for the office of secretary of state, held a secret meeting in Pyongyang with North Korea's leader Kim Jong Un two weeks ago.

The meeting was first reported by the Washington Post and took place around April 1. The White House has refused to comment.

According to the Post, Pompeo went to prepare for a direct talks between Trump and Kim about North Korea's nuclear weapons programme.

In a sign of how difficult negotiations might prove to be, Pompeo said last Thursday there would be no rewards for the isolationist state unless it agreed to dismantle its nuclear weapons programme irreversibly.

Speaking at his confirmation hearing, he said he was 'not optimistic', when asked if he believed North Korea would agree to dismantle its nuclear programme. He said that in past negotiations the United States and the world had relaxed sanctions too quickly.

'It is the intention of the president and the administration not to do that this time to make sure that...before we provide rewards, we get the outcome permanently, irreversibly, that it is that we hope to achieve,' he said.

North Korea is notorious for its treatment of dissidents, including religious believers. Tens of thousands of Christians are in labour camps, often held in appalling conditions. It is number one on the Open Doors World Watch List of countries where it is most difficult to be a Christian – a spot it has held for many years.