WASHINGTON, Jan 11 (Reuters) - U.S. and British strikes on Yemen were directed at Houthi military capabilities and sought to avoid collateral damage, and Houthi actions present a threat to the United States and the entire world, U.S. officials told reporters on Thursday.

No retaliatory action by the Houthis had occurred yet.

"While we fully expect this action to diminish the Houthis' capability and degrade it, and certainly over time to reduce their capacity and propensity to conduct these attacks, we would not be surprised to see some sort of response," one official told reporters on a conference call.

(Reporting by Jeff Mason, Phil Stewart, Idrees Ali and Eric Beech; Editing by Jacqueline Wong)