The Pentagon on Monday revealed an expansion of the U.S. air campaign against the Islamic State into Libya with great fanfare, touting the ability of U.S. air power to enable the Libyan government-backed forces "to make a decisive, strategic advance" against the Islamic State stronghold in Sirte, on the Libyan coast.

But a blow-by-blow accounting of airstrikes released by the U.S. Africa Command — showing a total of just nine as of Wednesday — revealed the relatively modest scope of the effort, which so far has taken out a couple of tanks, some heavy construction equipment, two vehicles, a single rocket launcher and a pick-up truck with a recoilless rifle mounted on it.

The Pentagon spent a lot of time this week explaining how the hit on a single tank on Monday was a small, but decisive, victory that facilitated the ongoing offensive by troops aligned with Libya's unity government, known as the GNA, or Government of National Accord.

Pentagon spokesman Navy Capt. Jeff Davis said the Islamic State tank located in a suburb just southwest of Sirte had proved to be "a menacing problem" for the anti-Islamic State forces.

"It was hidden in a group of trees. It was very close to buildings where civilians could have been, and it was something that was used repeatedly to beat back advances by the GNA," Davis said Tuesday.

A video released by the U.S. military shows the Russian-made T-72 tank survived a direct hit but was judged to be "disabled."

"It represented a challenge for them [the GNA forces] to get into the city," Davis said. "We have already seen that since we struck it, GNA forces have moved into that neighborhood.

The government-backed forces have been fighting Islamic State for months, and the U.S. is only now providing air support as victory seems close,

The idea, according to a Pentagon spokesman, is to "help them get across the finish line."

The Pentagon says both manned and unmanned aircraft are conducting the strikes at the request of, and in coordination with, the Western-backed unity government in Tripoli.

While the Pentagon declined to say where the U.S. aircraft were operating from, one Pentagon official confirmed U.S. Marine Harrier jump jets from the U.S. amphibious assault ship Wasp, conducted some of the strikes.

The U.S. says the air support will continue until the GNA troops drive the Islamic State out of Sirte.

"I don't want to put a timeline on it," Davis said, "but it's probably going to be weeks not months."