Sister of North Korea's Kim says US spy plane was repelled over exclusive economic zone

The sister of North Korean leader Kim Jong Un said Monday that Pyongyang's warplanes had forced the retreat of a U.S. spy plane over its territorial waters.

Kim Yo Jong, an influential partner of her brother's in North Korean government, alleged the U.S. Air Force spy plane intruded into territorial waters around 5 a.m. Monday before it was scared off by aircraft from the Democratic People's Republic of North Korea (DPRK).

Kim also alleged another U.S. spy plane crossed into DPRK territory a few hours later.

Kim said the DPRK "will not take a direct counteraction against the U.S. forces' acts of espionage outside the economic water zone of the DPRK side" but warned of "clear and resolute actions" if there is another incursion.

"If the U.S. has not yet realized what danger is directly coming to it in disregard of the DPRK's warning, the DPRK is not to blame for it," she said in a statement shared by North Korean state media.

Kim's comments come after a North Korean spokesperson also warned that approaching spy planes would be shot down.

There was no immediate word from Washington about the alleged incident.

South Korean Joint Chiefs of Staff spokesperson Lee Sung Joon denied the accusations of a spy plane crossing into North Korean territory.

He said the reconnaissance mission was a standard operation in coordination with South Korea.

North Korea and South Korea are divided by a demilitarized zone enacted nearly 70 years ago, and Pyongyang reacts fiercely to any illegal crossings over the border.

North Korea has stepped up its warnings against the U.S. and South Korea after the allied nations recently began conducting joint military drills again after a brief hiatus.

Amid concerns about a North Korean nuclear buildup, Washington also agreed this year to send a nuclear submarine to the peninsula, the first time a U.S. nuclear sub would be deployed to South Korea since 1981.