WASHINGTON (Reuters) - The momentum in the fight against Islamic State has shifted and the militant group has been driven out of almost half the territory it once occupied in Iraq, U.S. Secretary of State John Kerry said on Wednesday.

"The momentum has shifted," Kerry told the opening of an Iraq donor conference, saying he hoped the meeting would raise at least $2 billion for the war-torn country. "We are making progress with significant portions of Iraq reclaimed, significant portions of Syria now being reclaimed," he added.

(Reporting by Lesley Wroughton and Andrea Shalal; Editing by James Dalgleish)