The surprise news of Crocker's departure came hours after the conclusion of the NATO summit in Chicago, where he was in attendance with President Barack Obama, negotiating an agreement for drawing down NATO troops from Afghanistan, CBS reported.
Crocker would become the second American envoy to the region to quit. Last week, Washington Post reported that the US ambassador to Pakistan, Cameron Munter, was leaving his post in Islamabad , after serving just over 18 months in a country that has proved to be one of Washington's most challenging and difficult partners in the world.
CBS said US officials did not give a reason or an exact date for Crocker's impending departure from Kabul. But it quoted a state department official as saying that "Afghanistan is a tough place to serve."
Crocker was the US envoy who reopened the American Embassy in Kabul in 2002, after the ouster of Taliban regime and in recognition of his services he was awarded the Presidential Medal of Freedom, America's highest civilian honour in 2009.
He was Ambassador to Pakistan from 2004-2007 and to Syria from 1998-2001.
