Geneva - Tribute was paid Thursday to UN peacekeepers exactly 60 years after the first operation was authorized.

United Nations Under-Secretary-General and head of the UN office at Geneva Sergei Ordzhonikidze led a minute's silence to mark the International Day of United Nations Peacekeepers, and said, "We all owe them an eternal debt of gratitude."

"Dedicated to helping their fellow human beings, often in dangerous and difficult circumstances far from family and friends, peacekeepers embody the values and principles of the United Nations," Ordzhonikidze said.

More than one million United Nations peacekeepers had taken part in 63 operations since the mechanism was set up in 1948.

More than 2,400 peacekeepers had been killed in the service of peace, while millions of lives had been saved because of their bravery.

In 60 years the role of peacekeepers had evolved to facilitate humanitarian assistance, help refugees and displaced persons to return, and ensure conditions for democratic elections.

Peacekeeping was more complex than ever with over 110,000 military and civilian staff serving in 20 peace operations across nine time zones.

Currently large-scale missions in the Democratic Republic of Congo, Darfur, Chad and the Central African Republic brought new levels of complexity and risk.

The Blue Helmets, as peacekeepers are known, needed to respond to meet the new challenges and respond in emergencies.

"At the same time, we must not lose sight of the need to ensure long-term stability. If peace building efforts flounder, the gains of peacekeeping are lost," said Ordzhonikidze. (dpa)