(CNN) -- North Korea has decided to return a South Korean fishing boat and its crew, after the North's navy intercepted them in its waters in August, state-run media said Monday.
The illegal fishing operation in the Sea of Japan on August 8 was "an intolerable infringement upon the sovereignty" of North Korea, the KCNA news agency said.
The boat and crew will be returned for humanitarian reasons, though, KCNA said.
The crew of the "55 Daesung" acknowledged the gravity of their actions and promised not to repeat them, said the news agency, which also cited the South Korean Red Cross's request for leniency.
North Korea says the Sea of Japan is actually the East Sea of Korea.
In August, a U.S. congressman submitted a resolution urging North Korea to release the crew -- four South Koreans and three Chinese, according to South Korean state-run media.
North Korea's announcement comes as South Korea has delayed joint military drills with the United States.
Stormy weather has postponed the four-day exercises in the Yellow Sea, which were to start on September 5. A new date has not been announced.
The anti-submarine warfare exercises are "designed to send a clear message of deterrence to North Korea," said the United States Forces Korea.
The drills are to involve 1,700 navy and marine personnel from South Korea and the United States.
North Korea has repeatedly threatened retaliation for the drills.