The council made public an open letter addressed to the U.S. president at the press conference.

The letter said that lots of Koreans were brutally killed before and after the Korean war but the truth has been covered up for more than half a century.

The bereaved families of those who fell victim to the mass killings of civilians unprecedented in history in its cruelty are still suffering from agony, the letter said.

The wartime massacres were perpetrated in an organized and planned way, in particular, the letter noted, adding:

The south Korean "government" has concealed the truth of the case and destroyed evidence by abusing power for decades and the U.S. has kept mum about it.

The U.S. should clarify the truth behind the mass killings of civilians before and after the war.

The organization thrust the open letter to the U.S. embassy at the end of the press conference.