UNITED NATIONS (REUTERS) - Academy Award winner George Clooney has stepped down as a United Nations (UN) "Messenger of Peace," the UN said on Monday, suggesting the newly engaged actor did not have enough time for the role promoting the world body's peacekeeping efforts.

"After six years in this role, Mr Clooney feels it is time to retire his official role as Messenger of Peace," said UN spokesman Stephane Dujarric, wishing Clooney well on his engagement to human rights lawyer Amal Alamuddin. "The competing demands on their time from their professional and advocacy lives sometimes make it difficult for high-profile individuals to carry out a formal United Nations role," he said.

As a messenger of peace, Clooney travelled to Democratic Republic of Congo and South Sudan. Mr Dujarric said UN Secretary-General Ban Ki Moon hoped there would be future opportunities for collaboration between Clooney and the United Nations.

In 2010, Clooney helped found the Satellite Sentinel Project, which tracks human rights abuses and mass atrocities in Sudan.

"Retiring from his UN role will afford him the independence to move forward with this and other personal advocacy projects and activities," Mr Dujarric said.

When Clooney was named a UN Messenger of Peace in 2008, Mr Ban cited his work on raising awareness about violence in Sudan's conflict-torn western Darfur region, where he advocated for aid for the millions of people displaced by fighting.