The United States and Italy warned Tuesday that the "Islamic State" (ISIS) terrorist group is expanding its reach, threatening to seize Libya and launch attacks in Western countries, AFP reports.

But as representatives from the 23 countries of the US-led coalition battling the jihadists' self-declared "caliphate" reviewed their progress at talks in Rome, Italy and France made it clear military action against ISIS's Libyan wing is not on the immediate agenda.