An officials said they will not have any interest in talks if the US "corners us and unilaterally demands we give up nuclear weapons"
North Korea has cast doubt over Kim Jong Un's planned summit with Donald Trump next month.
Both men are due to meet in Singapore on June 12th, following an apparent easing of tensions on the Korean peninsula.
However, North Korea's first vice foreign minister Kim Kye Gwan said that if the US "corners us and unilaterally demands we give up nuclear weapons we will no longer have an interest in talks".
He added: "[We] will have to reconsider whether we will accept the upcoming DPRK-US summit".
North Korea has also scrapped high-level talks with the South as a result of military drills that Seoul is conducting with the US.
Both countries regularly take part in drills, which typically provoke an angry response from the North.
North Korean media described the latest drills as a "deliberate military provocation".
During an historic summit last month, both Kim Jong Un and South Korean President Moon Jae In pledged to work towards achieving the 'complete denuclearisation' of the peninsula.
Donald Trump has publicly expressed optimism about the planned talks with Mr Kim, saying "we will both try to make it a very special moment for World Peace".
However, North Korea has criticised Mr Trump's national security adviser John Bolton.
Kim Kye Gwan said his country does not hide their 'feelings of repugnance' towards Mr Bolton, BBC reports.
Mr Bolton - who has in the past suggested a preemptive strike against North Korea - has proposed the North follows a 'Libya model' for nuclear disarmament.
Libya agreed to cut its nuclear programme in exchange for the easing of sanctions - but commentators have suggested North Korea may want a greater range of assurances in return for denuclearisation.