US Secretary of State Mike Pompeo has set off for his next round of North Korea denuclearisation negotiations, on a three-day trip that will also take him to Japan, South Korea and China.
Talking to reporters on board his flight from Washington, he refused to give details of what would be discussed in Pyongyang on Sunday but said his goal was "to make sure that we understand what each side is truly trying to achieve."
North Korean leader Kim Jong-un agreed to denuclearise the Korean Peninsula following his unprecedented summit with US President Donald Trump in Singapore in June.
However, the agreement was criticised for lacking detail on how that would be achieved and negotiations appear to have since stalled.
Kim refused to meet Pompeo during his last trip to Pyongyang in July.
On Friday, Pompeo said it was possible the two sides may work out a date and location for a second meeting between Trump and Kim.
However, he refused to be drawn on whether the US would accede to North Korean demands for an official declaration to end the 1950-53 Korean War.
Experts say such a declaration could lead to questions about the legitimacy of the thousands of troops the US has stationed in South Korea.
Pompeo also refused to say whether he would follow Seoul's suggestion to not ask for an inventory of North Korea's nuclear capabilities, which South Korea fears would further stall negotiations.
The top US diplomat is also set to hold talks in Tokyo on Saturday, in Seoul on Sunday and Monday and in Beijing on Monday.
