US President Donald Trump says there is "no time limit" for North Korea to denuclearise and that there is no need to rush the process.
It marks a shift in tone from Trump who previously said nuclear disarmament would start "very quickly".
Last month, the US president and North Korean leader Kim Jong-un held historic talks and pledged to denuclearise the Korean peninsula.
The accord did not have a timetable for the process or plan to carry it out.
Since the meeting between Trump and Kim on 12 June, there has been little reported progress towards denuclearisation, says the BBC.
Last week North Korea accused the US of making "gangster-like" demands for the process, and branded the US attitude at high-level talks as "extremely troubling".
Trump said on Tuesday that talks with Pyongyang were going fine.
"We have no time limit. We have no speed limit," the US president told reporters.
"Discussions are ongoing, and they're going very, very well," he said.
"The sanctions are remaining. The hostages are back. There have been no tests. There have been no rockets going up for a period of nine months, and I think the relationships are very good, so we'll see how that goes."
The US president also said North Korea's nuclear threat had been a major topic during his meeting with Russian President Vladimir Putin earlier this week.
"President Putin is going to be involved in the sense that he is with us," Trump said.
The president's latest comments on the timeline for denuclearisation appear to shift from his position ahead of the summit with Kim, when he said denuclearisation should start "without delay." Following the meeting, he said the process would start "very quickly".
But since then, Trump has suggested that dismantling North Korea's nuclear arsenal could be some way off.
Speaking at a press conference in the UK last week, the US president said negotiations with Pyongyang would be "probably a longer process than anybody would like".
Following the 12 June meeting, US Secretary of State Mike Pompeo said he hoped to see "major disarmament" by North Korea by the end of 2020.