North Korea has rejected any new talks with South Korea, apparently opposed by the South Korean leader.
The country's reunification committee issued a statement in response to an address by South Korean President Moon Jae-in on Thursday.
Early Friday, North Korea tested two missiles in the sea off its east coast, the South Korean army announced.
It is the sixth test of this type in less than a month.
Six days ago, North Korea launched two short-range ballistic missiles in the Sea of Japan.
The series of tests came after US President Donald Trump and North Korean leader Kim Jong-un decided at a meeting in June to restart negotiations on denuclearization.
North Korea has faced international sanctions for the development of its nuclear weapons.
What did South Korea say?
In his speech, marking Korea's liberation from Japanese power, President Moon promised to unite the Korean peninsula by 2045.
Korea split into two countries at the end of World War II.
President Moon said that the goal of achieving denuclearization on the Korean peninsula was at its "most critical point", while negotiations between the North and the South seem to be stalled.
"A new Korean peninsula, one that brings peace and prosperity to ourselves, in East Asia and the world, is waiting for us," he said in a televised speech.
What was the reaction of North Korea?
In a statement, the North questioned the meaning of the dialogue "when joint military exercises against us in South Korea are in full swing".
"What is clear is that it's all about destroying us," said a spokesman about the military drills that began last week.
North Korea expressed anger over the US-South Korea military exercises, saying they were violating agreements with US President Donald Trump and Mr. Jae-in.
He previously described them as a "war rehearsal".
- North Korea fires missiles as South launches joint exercise with the United States
In a recent letter to Mr Trump, North Korean leader Kim Jong-un reportedly complained of "ridiculous and costly military exercises".
The stalemate in the denuclearization talks is entirely due to South Korea's decision to hold the exercises, the Northern spokesman said on reunification.
"We have no more words to talk with South Korean officials," said the official in a statement issued by the state-run Korean news agency.