Peace can only be preserved and strengthened by showing kindness, understanding, respect, consideration, solidarity and heart, and by rejecting hatred, said Pahor at the ceremony taking place at the ossuary for the victims of World War I at Ljubljana's central cemetery.

"The world is never just pushed into war. It is forced into war by irresponsible judgements and decisions. Wars, especially world wars, are not the natural state of human society. People decide about wars and peace," said Pahor.

He said that memories of World War I in Slovenia "rested for long years in intimate, private remembrance. "But at least from the the 100th anniversary onwards this period deserves to be labelled as a milestone for our history as a nation."

This goes for "the time during the war ... and the time immediately after it, when the path was cleared for political formation of the Slovenian nation".

The ceremony was also attended by Speaker Dejan Židan and the National Council President Alojz Kovšca, several ministers and representatives of the judiciary, police, military and religious communities, as well as members of the diplomatic corps in Slovenia.

Židan said in a message he released after the ceremony that peace required constant alertness, work and effort from everybody, be it individuals or states. It also requires respect for human rights, solidarity, fight against prejudice, intolerance and hatred.

World War I did not solve any of the problems that led to it, said the speaker. In its wake, it left tragic figures, said the speaker, listing millions of victims, human distress, devastated landscapes, an exhausted Europe and broken empires.