ROME (Reuters) - Italy is resisting pressure to allow aircraft and armed drones to stage attacks on Islamic State militants in Libya from its territory, saying on Thursday that direct Western military intervention on the ground there was “unthinkable”.

While Libya’s rival factions have struggled to agree to a UN-backed national unity government, the Americans have launched air strikes on Islamic State outposts in the country and the French have conducted surveillance flights and sent military advisers.

But the U.S. and the EU have both said they agree with Italy that deeper military involvement will need the request of the Libyan government.

Italy is concerned that Western military intervention without such a request will stoke IS popularity and turn Libyan militias against the West. It is trying to persuade its allies to limit action until a government is in place.

“Libya can be stabilized by local forces. A military intervention and occupation of the country (by Western forces) would be unthinkable,” Italian Defence Minister Roberta Pinotti said in an interview on Canale 5 television.

When asked about reports of French special forces on the ground there, she said: “In the past, unilateral accelerations have not helped Libya.”

She was referring to the Western bombing that helped depose Libyan strongman Muammar Gaddafi five years ago but which has led to civil war and chaos, allowing IS to take root just across the Mediterranean from Europe.

Italy’s Sigonella air base, where U.S. and NATO forces also are stationed, is just 500 km (310 miles) from Tripoli, making it the West’s best staging area for air strikes on Libya.

Italy has more at stake than its allies, as people smugglers based in Libya have sent some 300,000 migrants across the sea over the past two years, and state oil giant Eni has extensive gas and oil interests there.

There needs to be “patience and encouragement” to cajole the Libyan factions toward a unity government, an Italian defense official said, because that remains “the only road to go down”.

Last week, a U.S. air raid on Sabratha killed more than 40 Islamic State fighters. Instead of making the short flight from Sigonella in Sicily, the planes flew all the way from Britain.

After months of negotiations, Rome has agreed to let the U.S. fly armed drones from Sigonella, but they can only fire their missiles after receiving specific approval from Italy and only in missions to defend U.S. or “coalition allies”.

Washington had sought permission to use the armed drones without any preconditions. Italian insistence on giving the green light to any operation will seriously limit their scope.

The United Nations has been trying to bring Libya’s rival factions together in a unity government. A presidential council has been formed, but hardliners are resisting a vote in Libya’s elected parliament to approve the new government.

On Tuesday, Libya’s eastern parliament put off the vote yet again. A majority of lawmakers issued a statement of support for the government, saying hardliners had used force and threats to prevent a vote from taking place.

U.N. envoy Martin Kobler urged the parliament’s leadership to “take immediate steps to formalize this endorsement”.