BEIRUT (AP) — Lebanon's U.S.-backed military is gearing up for a long-awaited assault to dislodge hundreds of Islamic State militants from a remote corner near Syrian border, seeking to end a years-long threat posed to neighboring towns and villages by the extremists.

The campaign will involve cooperation with the militant group Hezbollah and the Syrian army on the other side of the border — although Lebanese authorities insist they are not coordinating with Syrian President Bashar Assad's government.

But the assault could prove costly for the under-equipped military and risk activating IS sleeper cells in the country.

The tiny Mediterranean nation has been spared the wars and chaos that engulfed several countries in the region since the so-called Arab Spring uprisings erupted in 2011. But it has not been able to evade threats to its security, including sectarian infighting and random car bombings, particularly in 2014, when militants linked to al-Qaida and IS overran the border region, kidnapping Lebanese soldiers.