North Korea's Kim turns 40. But there are no public celebrations of his birthday

North Korean leader Kim Jong Un turns 40 on Monday with no announced public celebrations at home

SEOUL, South Korea -- North Korean leader Kim Jong Un turned 40 on Monday with no announced public celebrations at home, after he entered the new year with artillery barrages into the sea and vows to expand his nuclear arsenal.

Since taking power in late 2011, Kim, the third generation of his family to rule North Korea, is believed to have established an absolute leadership similar to his predecessors. But his birthday has yet to be officially celebrated, unlike his late father Kim Jong Il and grandfather Kim Il Sung. Their birthdays are two of the North's biggest holidays and are marked with great fanfare, loyalty campaigns and sometimes massive military parades.

On Monday, North Korea’s state news agency published a lengthy article extolling Kim’s guidance of major construction projects in the past decade. It also reported Kim visited a chicken farm with his daughter the previous day. But it made no mention of his birthday.

Some observers speculate Kim may think he’s still relatively too young or needs bigger achievements to hold such lavish birthday festivities. Others say the lack of a public birthday bash may be related to his concerns about attention to his late Japan-born mother.

Kim's headlong pursuit of a bigger nuclear arsenal has invited punishing U.S.-led sanctions, which together with border closures during the pandemic were believed to have badly hurt the North's fragile economy. Kim has subsequently admitted policy failures as his vow that North Korea would “never have to tighten their belts again" remained unfulfilled.