Placards placed in downtown Pyongyang last year that celebrated North Korea's nuclear test have disappeared.

A North Korea expert who recently visited the communist country said the placards have been replaced by ones pledging to rebuild the North Korean economy or improve people's livelihoods.

The source said the placards promoted the improvement of the public's livelihood and making a great change this year, which marks the 95th anniversary of the birth of the late North Korean leader Kim Il-sung and the 75th anniversary of the North Korean military.