Kerry warns IS 'days numbered' after 'Jihadi John' hit

US Secretary of State John Kerry speaks during a press conference with his Tunisian counterpart Taieb Baccouche, on November 13, 2015 at the foreign ministry in Tunis (AFP Photo/Fethi Belaid) (AFP)

Tunis (AFP) - US Secretary of State John Kerry on Friday warned the Islamic State jihadist group its "days are numbered", following an American strike in Syria targeting British militant "Jihadi John".

"The coalition forces conducted an air strike targeting...Jihadi John," whose real name is Mohammed Emwazi, he said on a visit to Tunis.

"We are still assessing the results of this strike but the terrorists associated with Daesh need to know this: Your days are numbered and you will defeated," said Kerry, using the Arabic acronym for IS.

"There is no future, no path forward" for IS, the secretary of state said.

The Pentagon said the US military conducted an air strike Thursday targeting Emwazi, the masked IS militant with a British accent seen in grisly videos executing Western hostages.

"We are assessing the results... and will provide additional information as and where appropriate," said spokesman Peter Cook.

The Pentagon said the air strike took place in Raqa, the IS's de facto Syrian capital.

CNN and the Washington Post, citing officials, reported that Emwazi was targeted by a drone.