Crowley said Holbrooke, 69, fell ill when he was working on the seventh floor of the State Department building, where the office of Secretary of State Hillary Clinton is located, Xinhua reported.
He, however, did not give any details about Holbrooke's condition, saying the senior diplomat was in hospital for evaluation.
Holbrooke was appointed Jan 22, 2009 as the special envoy for Pakistan and Afghanistan by the Obama administration.
Published 11 December 2010, 02:17 IST