President Donald Trump with North Korea's Kim Jong Un in Vietnam (Picture: PA).
United States secretary of state Mike Pompeo has said America expects North Korean leader Kim Jong Un to live up to his promise to Donald Trump to continue his moratorium on missile launches and nuclear tests.
It is after a senior North Korean official said earlier on Friday that Mr Kim will soon decide if he wants to continue diplomatic talks and whether to continue to refrain from missile launches and nuclear tests.
"In Hanoi, on multiple occasions, he spoke directly to the president and made a commitment that he would not resume nuclear testing nor would he resume missile testing," Mr Pompeo said amid new tension between the two countries.
"So that's Chairman Kim's word. We have every expectation he will live up to that commitment."
North Korean Vice Foreign Minister Choe Son Hui said: "I want to make it clear that the gangster-like stand of the US will eventually put the situation in danger. We have neither the intention to compromise with the US in any form nor much less the desire or plan to conduct this kind of negotiation."
Earlier this month, satellite images of a facility near Pyongyang emerged, suggesting North Korea could be preparing to launch a missile or satellite.
The images detailed a site known as Sanumdong, where North Korea has assembled some of its intercontinental ballistic missiles and satellite-launching rockets.
Photographs, taken on 22 February by DigitalGlobe, show rail cars sitting in a nearby rail yard as well as two cranes and trucks.
"When you put all that together, that's really what it looks like when the North Koreans are in the process of building a rocket," Jeffrey Lewis, director of the East Asia Nonproliferation Project at the Middlebury Institute of International Studies at Monterey, told US broadcaster, the National Public Radio (NPR).
It follows reports that North Korea's main rocket launch site at Sohae has been rebuilt.
Work to dismantle Sohae began last year but stopped as US talks stalled.
Mr Lewis, who studied the images, told NPR that it was impossible to know whether North Korea was preparing a military missile or a rocket that could carry a civilian satellite into space.
He further cautioned that it was impossible to know when any launch could happen.