This undated picture released from North Korea's official Korean Central News Agency (KCNA) on April 10, 2014 shows North Korean leader Kim Jong-Un in a suit which was published on the front page of the Rodong Sinmun on April 10.
North Korean leader Kim Jong-Un paid respects to his grandfather Kim Il-Sung as the country marked the birthday Tuesday of its late founder with renewed calls for loyalty to the ruling Kim dynasty.
At the stroke of midnight, Kim Jong-Un, accompanied by top military leaders, visited the Kumsusan Palace of the Sun in Pyongyang -- the mausoleum holding the embalmed body of his grandfather, the North's official KCNA news agency said.
The similarly preserved body of Kim's father, Kim Jong-Il, whom he succeeded as leader in December 2011, is housed in the same building.
"Kim Jong-Un, together with other visitors, paid homage to Kim Il-Sung in the humblest reverence for him," KCNA reported.
Kim Il-Sung died of a heart attack in 1994. His birthday is known as the Day of Sun in North Korea and is a major national holiday.
The centenary of his birth in 2012 was marked by a major military parade and Kim Jong-Un's first public speech.
There were no indications of a similar parade being prepared Tuesday, but the South's Yonhap news agency cited officials as saying Pyongyang might be readying a symbolic show of military force.
"Artillery pieces including multiple rocket launches and self-propelled guns are being assembled near Pyongyang," it quoted an unidentified government official as saying.
The official said it was "highly likely" the North may carry out a large scale drill on Friday, to coincide with the end of South Korea's annual joint military exercises with the United States.
In an address to top military, party and government leaders to mark Tuesday's holiday, the North's nominal head of state, Kim Yong-Nam, urged all military personnel to pledge their loyalty to Kim Jong-Un.
"Being loyal to Comrade Kim Jong-Un's leadership is the decisive guarantee to carry forward with the Great Comrade Kim Il-Sung and Kim Jong-Il's thoughts and accomplishments," he was quoted as saying by the ruling party newspaper, Rodong Sinmun.
"No matter what winds may blow, we must put firm faith in Dear Leader Kim Jong-Un and follow his lead," Kim said.
The daily carried a front page portrait of a beaming, bespectacled Kim Il-Sung standing against the backdrop of Mount Paektu -- seen by many Koreans as the place of their ancestral origin.
Tensions on the Korean peninsula traditionally rise around the time of the annual South Korea-US military exercises, which the North regularly condemns as rehearsals for invasion.
In a pointed protest at the exercises, Pyongyang carried out a series of rocket and missile launches including, on March 26, its first mid-range missile test since 2009.
The two Koreas also traded artillery fire into the waters across the tense Yellow Sea border on March 31 and North Korea warned that it might carry out a "new" form of nuclear test -- a possible reference to a uranium-based device or a miniaturised warhead small enough to fit on a ballistic missile.