US officials say Egypt and the UAE were behind air strikes in Libya last week that targeted Islamist-linked militia.
A senior US official told the BBC that Washington was not consulted about the attacks and was "caught off-guard".
The air strikes on militia positions around Tripoli's international airport were reportedly carried out by Emirati fighter jets using bases in Egypt.
The Egyptian authorities have denied involvement, and there has been no direct comment from the UAE.
The strikes failed to stop militias from Misrata and other cities, which operate under the banner Libya Dawn and include some Islamist groups, seizing the airport from a militia from Zintan that had controlled it since 2011.
More, plus video report:
http://www.bbc.co.uk/news/world-africa-28933070
