North Korea has warned the US about using "pressure and military threats" against it as the two countries prepare for a historic summit.
A Foreign Ministry official said the US was deliberately provoking the North by suggesting sanctions will not be lifted until it gives up nuclear weapons.
US President Donald Trump and North Korean leader Kim Jong-un are due to meet in the next few weeks.
It will be the first ever meeting between the two countries' leaders.
North and South Korean leaders agreed last month to denuclearise the region, at a border summit which came after months of warlike rhetoric from the North and Mr Trump.
Mr Kim became the first North Korean leader to set foot in South Korea since the end of the Korean War in 1953.
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North Korea regularly criticises the US - but there have been few attacks in recent weeks, amid plans for the summit.
This latest statement is a reminder that discussions between the two countries will not be easy, says BBC Asia editor Michael Bristow.
The North Korean official, quoted by state news agency KCNA, said that Washington was "misleading public opinion" by saying the denuclearisation pledge resulted from sanctions and other pressure.
The US was also aggravating the current good atmosphere by deploying military assets on the Korean peninsula, they added.
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"The US is deliberately provoking [North Korea] at the time when the situation on the Korean peninsula is moving toward peace and reconciliation thanks to the historic north-south summit and the Panmunjom Declaration," the statement said.
"This act cannot be construed otherwise than a dangerous attempt to ruin the hard-won atmosphere of dialogue and bring the situation back to square one.
"It would not be conducive to addressing the issue if the US miscalculates the peace-loving intention of [North Korea] as a sign of 'weakness' and continues to pursue its pressure and military threats against the latter."
Mr Trump has said he will maintain sanctions and other pressure on the North and suggested that his tough stance has helped facilitate reconciliation.
On 27 April Mr Kim met South Korean President Moon Jae-in at the border village of Panmunjon.
They said they would pursue talks with the US and China to formally end the Korean War, which ended in 1953 with a truce, not total peace, and made a commitment to the aim of "a nuclear-free Korean peninsula".
Mr Trump says a date and venue for the talks have been decided, but has not revealed them.