President Barack Obama will make a public statement at the White House to comment on the attacks in Libya that killed US Ambassador Chris Stevens and three other Americans.
The White House says Obama will be joined by secretary of state Hillary Clinton. His remarks are scheduled for 10.35am (1430 GMT).
Stevens was killed, Libyan officials say, when he and embassy aides went to the US consulate in Benghazi, which was under attack by protesters angry over a film that ridicules Islam's Prophet Muhammad.
Obama was notified that Stevens was unaccounted for on Tuesday night and was told of his death on Wednesday morning.