The US envoy for North Korea has returned from Pyongyang.
Stephen Biegun had was there to hold talks in preparation for a second US-North Korean leadership summit.
After three days in discussions, US officials said Biegun would meet his counterpart again soon.
US President Donald Trump recently confirmed that he would meet North Korea's Kim Jong-un in Vietnam, on 27-28 February.

Man charged with 10 counts of attempted murder after knife attack on UK train
Tanzania's Hassan sworn into office after deadly election violence
Powerful 6.3 quake kills at least 20 in Afghanistan, hundreds injured
Turkey set to call for action on Gaza as soon as possible, source says
