MOSCOW • It was meant to be a news conference about solving the Syria crisis and combating the Islamic State in Iraq and Syria, but an unguarded remark into the microphone from Russia's Foreign Minister Sergei Lavrov grabbed all the attention.

Even a former US ambassador to Moscow joined the social media storm triggered after Mr Lavrov let slip the less than diplomatic language on Tuesday as he and his Saudi counterpart Adel al-Jubeir met the press.

Taped footage showed Mr Lavrov checking his mobile phone, making notes, adjusting his glasses, rubbing his forehead and then saying quietly: "F***ing morons."

It was not clear who or what Mr Lavrov was referring to and his spokesman, who was present, said she did not hear the minister swear and that the talks went well.

The two had earlier failed to resolve a disagreement over Syrian President Bashar al-Assad's fate.

The reaction on social media included a contribution from former US envoy Michael McFaul in response to a suggestion that Mr Lavrov had aimed the comment at the Saudi minister.

"Really? And he used to accuse me of undiplomatic language," Mr McFaul wrote on Twitter.

Mr Lavrov's spokesman said he was not annoyed about the talks with Mr Jubeir. "I cannot comment on what is not related to the essence of the talks," she said.

"Interjections, noises, sneezing - I think it is unnecessary to comment on lip reading. Everyone hears differently."

A Reuters photographer and cameraman present said the remark by Mr Lavrov, known for getting annoyed with photographers, appeared aimed at those who started snapping pictures as he raised his hand to adjust his glasses.

REUTERS