The US State Department has apologised over comments made by a State Department official about Libyan leader Muammar Gaddafi.

When Mr Gaddafi two weeks ago called for jihad, or holy war, against Switzerland, a State Department spokesman dismissed his words, saying they had not made any sense.

The Libyan ambassador to the US later sought to clarify Col Gaddafi's remarks about Switzerland, saying the word jihad was meant to suggest an economic boycott rather than an armed attack.

The man who made the dismissive comments, PJ Crowley, has now apologised to the Libyan leader, saying the words were not intended to offend.

At the time of the Libyan leader's comments Libya and Switzerland had been embroiled in a long-running diplomatic row over the detention in Switzerland of Gaddafi's son and the Swiss vote against the building of minarets.

Last week, Libya's National Oil Corporation warned US oil firms there could be possible repercussions due to Mr Crowley's statement.

In his apology to the Libyan leader, Mr Crowley said: "I regret that my comments have become an obstacle to further progress in our bilateral relationship. I should have focused solely on our concern about the term jihad, which has since been clarified by the Libyan government."