North Korean leader Kim Jong-un, right, and his daughter Kim Jue-ae attends a banquet celebrating the 75th founding anniversary of the Korean People's Army during a visit to lodging quarters of KPA General Officers in Pyongyang, on Feb. 7. EPA-Yonhap

The first child of North Korean leader Kim Jong-un is a son, while the gender of his third child has not been confirmed, South Korea's spy agency National Intelligence Service (NIS) was quoted as saying Tuesday.

The NIS also briefed the parliamentary intelligence committee that the North is expected to conduct large-scale military exercises in March and April that could possibly include the firing of a newly developed solid-fuel intercontinental ballistic missile (ICBM), according to Rep. Yun Kun-young of the main opposition Democratic Party.

"We do not have detailed evidence that his first child is a son. But we are convinced that the first child is certainly a son based on intelligence that has been shared with an external intelligence agency," Rep. Yoo Sang-beom of the ruling People Power Party quoted the NIS as saying.

Yoo said rumors that his son has physical and mental issues have not been confirmed.

Last year, Kim revealed his apparent second child, Ju-ae, a daughter, for the first time in photos showing them attending the test-firing of an ICBM. She has since been shown accompanying leader Kim to various events and meetings, spurring speculation she might be being groomed as his successor.

But Kim's first and third children have never been seen in public.

In a text message sent to reporters, the NIS later said it is in the process of verifying intelligence that Kim's first child is a son.

On Ju-ae, Yoo said she has not enrolled in any official academic organization so far and has been educated at home.

She enjoys hobbies such as horseback riding, swimming and skiing, and Kim is especially satisfied with her horseback riding skills, according to intelligence, Yoo said.

The lawmaker said the NIS has not yet detected orders by the North Korean authorities forcing people named Ju-ae to change their names as reported in some media outlets.

In regard to North Korea's possible large-scale military exercises, Yun said there are chances the North may deploy reconnaissance satellites in April in line with Kim's instruction.

The lawmaker said the possibility of Pyongyang test launching an ICBM to fly at a normal trajectory cannot be ruled out considering technological demand and recent warnings issued by Kim Yo-jong, the North Korean leader's sister.

On Tuesday, she warned the North is ready to take "overwhelming" actions against military activities by the Washington and Seoul, as its rivals are staging joint military drills involving American strategic assets.

The NIS also reported the North is believed to be short of about 800,000 tons of rice annually, but the number of people starved to death is not at a level that poses a threat to the regime, according to the lawmakers. (Yonhap)