Human rights expert Juan Mendez (search) was named to a new U.N. post to provide early warning about situations that could result in genocide, the United Nations announced Monday.

Mendez, a lawyer twice imprisoned in his native Argentina for political and professional activities, worked with Human Rights Watch for 15 years and is currently the president of the International Center for Transitional Justice (search) in New York, which assists countries pursuing accountability for mass atrocities or human rights abuses.

"I'm very honored, and at the same time the responsibility is beginning to weigh on me. It's an important job," Mendez told The Associated Press from London.

Annan created the post of U.N. special adviser on the prevention of genocide in March as the world was about to mark the 10th anniversary of the Rwanda genocide (search).

Mendez said that the United Nations (search) can play a crucial role in preventing future genocides because of its reach.

"There is no other international organization that can play a preventative role," he said.

In creating the post, Annan wanted a special adviser to collect information "on massive and serious violations of human rights and international humanitarian law of ethnic and racial origin that could lead to genocide," said U.N. associate spokeswoman Marie Okabe, who announced the appointment.