Secretary-General Ban Ki-moon designated George Clooney as a U.N. "messenger of peace" Friday to promote the world body's activities, especially in its far-flung peacekeeping missions.

The 46-year-old actor has been campaigning for an end to the 4 1/2-year war in Darfur and for humanitarian aid for the millions caught up in the conflict. He will become the ninth U.N. peace envoy.

While many U.N. agencies have goodwill ambassadors to promote activities ranging from helping children and refugees to promoting human rights, "messengers of peace" are selected by the secretary-general to promote the broader work of the United Nations.

U.N. spokeswoman Michele Montas said Clooney was recognized "for focusing public attention on crucial international political and social issues."

As a messenger of peace, he will have "a special focus on United Nations peacekeeping," Montas said.

Clooney will receive his designation at U.N. headquarters Jan. 31. He will also attend a meeting of countries that contribute troops to the 17 U.N. peacekeeping missions in countries from the Mideast and Africa to Haiti, Afghanistan and East Timor.

The 17 missions, with more than 100,000 personnel, include 73,000 troops and more than 9,000 international police. One of the newest missions is a joint African Union-U.N. peacekeeping force for Darfur that started deploying this month.

The other messengers of peace are Michael Douglas, Elie Wiesel, Jane Goodall, Yo-Yo Ma, Daniel Barenboim, Paulo Coelho, Midori Goto and Princess Haya of Jordan.

Clooney is a co-founder of Not on Our Watch, a humanitarian organization that focuses global attention on the plight of Darfur's people. The organization has raised more than $9.3 million for humanitarian efforts in the region.