Jim Michaels

USA TODAY

The Pentagon says it is encouraged by progress Libyan militias are making in driving the Islamic State from its stronghold in the oil-rich country, but is not offering new military assistance for a unity government that still lacks allegiance from some of the militias.

“Our focus is to be prepared to support the (new government) as they strive to assume responsibility for the security for all Libyan people,” said Lt. Col. Michelle Baldanza, a Pentagon spokeswoman. “At this time, we have not been asked to provide support.”

The Islamic State had expanded to as many as 6,000 fighters in Libya over the past year, capitalizing on disarray that followed the collapse of the Moammar Gadhafi regime in 2011. Gadhafi's government was overthrown by opposition forces within his country with the backing of a NATO-led coalition air campaign.

Militias from the western city of Misrata launched a surprise offensive in recent days to retake the militants' stronghold, the coastal city of Sirte, driving them from parts of the city.

The offensive comes as a U.N.-backed unity government attempts to establish control over rival factions based primarily in the capital, Tripoli, and the eastern city of Benghazi, site of the lethal 2012 attack on a U.S. compound.

The Pentagon has launched airstrikes against militants in Libya and sent teams of Special Forces into the country to establish links with militias there. But two years ago, the United States and its allies suspended plans to train Libyan forces at bases outside the country as the security situation deteriorated and the government split into rival factions.

Airstrikes and raids are not sufficient to defeat the Islamic State without a ground force to establish long-term security, according to the Pentagon.

The Pentagon has not decided yet whether to restart the training program or provide other support to the unity government.

“We’re obviously watching it very closely and very encouraged by what we see,” Peter Cook, the Pentagon press secretary, said last week.

The approach in Libya is a key test for President Obama’s strategy for defeating the Islamic State in Iraq. It provides support to local ground forces, who carry out the brunt of fighting.

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In Libya, local militias are showing a willingness to fight the militants, but the new government has not established control over the country and has not requested American or other foreign help. The United States wants to avoid backing a single militia over others and wants to be invited in by a government with broad support.

“What they’re afraid of is undermining the national unity government by an unauthorized foreign intervention,” said Daniel Serwer, a scholar at the Middle East Institute. “It might look like hesitation to some,” Serwer said. “It looks like wisdom to others.”

There have been some favorable signs. The Misrata militias leading the fight in Sirte have announced support for the new government. But a key leader in the east, Gen. Khalifa Haftar, has not announced his support for the new government.

Serwer said the new government wants to win support from factions in the east before requesting U.S. and international support.