The United Nations has become a terrorist target with increasing deadly attacks taking place since 2003, UN Secretary General Ban Ki-moon said.
The UN paid tribute to the more than 15 UN staffers killed in Algiers in 2007 when the UN office in the Algerian capital was bombed. The office housed several UN organisations involved in development assistance as well as child welfare.
"We are here to remember, and pay tribute to, the dear colleagues and friends we lost in the horrific bomb attack in Algiers two years ago today," Ban said Friday in a statement.
Ban also spoke of the attack against the UN office in Baghdad in August 2003, which killed 22 staffers, including chief of mission Sergio Vieira de Mello.
UN offices in Afghanistan and Pakistan were attacked this year, with deadly impact on UN personnel.
"The UN is now a target of terrorist groups," Ban said. "We are still considering all the implications of this fact."
Ban said he is working with the UN department of safety and security to ensure "the safest conditions" for employees working in the field.
"UN staff are on the ground throughout the world not to benefit one group or another, but to strive for global peace and security, for human rights and for development, for all the world's people. We are there to realize the great ideals found in the UN Charter," he said.