The move may call the planned meeting between Donald Trump and Kim Jong Un into question
North Korea has said it is scrapping high-level talks with the South due to military drills with the US, reports from the region say.
It has appeared to question the US' commitment to a summit between US President Donald Trump and North Korean leader Kim Jong Un set for next month in Singapore.
The joint Max Thunder drills between the South Korean and US air forces are a rehearsal for the invasion of the North, the North's Korean Central News Agency (KCNA) said.
They are also a provocation amid warming inter-Korean ties, KCNA said.
"This exercise targeting us, which is being carried out across South Korea and targeting us, is a flagrant challenge to the Panmunjom Declaration and an intentional military provocation running counter to the positive political development on the Korean Peninsula," the KCNA report said.
"The United States will also have to undertake careful deliberations about the fate of the planned North Korea-US summit in light of this provocative military ruckus jointly conducted with the South Korean authorities."
High-level talks between the Koreas had been due to take place in the southern side of the truce village of Panmunjom to discuss follow-up measures to the leaders' summit last month.
The military drills started on Friday, with about 100 warplanes.
The US and South Korea regularly carry out military drills.
However, in January Mr Trump and South Korean President Moon Jae In agreed to not hold the drills during the Winter Olympic Games in February after a diplomatic breakthrough with the North's leader.
But they agreed to resume the exercises, which involve tens of thousands of troops from both countries, after the Olympics.