The letter extended best wishes to Kim Jong Un on the occasion of the birth anniversary of President Kim Il Sung, Apr. 15.

It said the DPRK built socialist society based on the Juche idea.

It praised Kim Jong Un for further developing the Juche idea as required by the present era as President Kim Il Sung and General Secretary Kim Jong Il did.

Songun politics is providing a firm guarantee for independence of the DPRK, the letter said.

It supported the DPRK's measures for self-defence and struggle against imperialism.

It also expressed belief that the DPRK will register successes in improving the standard of people's living through dynamic economic construction under the wise leadership of Kim Jong Un.

The day will certainly come when Korea is reunified independently and peacefully without outsiders' interference, concluded the letter.