US Secretary of State Mike Pompeo is now in Pyongyang for the first major diplomatic talks on denuclearization since Donald Trump and Kim Jong Un's meeting in Singapore. Our correspondent Jack Barton has more from Seoul.

JACK BARTON SEOUL "U.S. Secretary of State Mike Pompeo is in Pyongyang really trying to achieve three main things. One is to get a list or at least a commitment to provide a list, or a commitment to providing a list of how many weapons Pyongyang possesses.

The second is to work out the inspection regime, who will inspect the dismantling of the nuclear stockpiles if and when that actually happens though as we understand it they won't be talking about how the dismantling of that nuclear and missile program will go ahead, and finally a timeline, how long will all of this take?

The U.S. is pushing for a speedy timeline, perhaps one year according to U.S. national security advisor John Bolton the D.P.R.K. pushing for something much longer. But there are obstacles in the way with some in the U.S. calling the meeting make or break amid widespread media reports that far from halting or dismantling it’s nuclear program the D.P.R.K. has been accelerating the enrichment of uranium and the building of missiles, so all of this going on in the background adding extra pressure. So all of this going on and again, analysts here and in Japan not expecting a big breakthrough, but enough that can hopefully keep this peace process alive. Jack Barton, CGTN, Seoul."