For the moment, at least, the once-obscure Syrian town of Kobane, along the Turkish border, has become the epicenter of the overall U.S. and coalition fight to degrade and demoralize Islamic State militants.

Airstrikes in and around the town have sharply increased, to nearly 40 in a 48-hour period this week. At the same time, strikes elsewhere in Syria have virtually stopped. Air attacks in neighboring Iraq have slowed significantly in recent days, in part because of bad weather and poor visibility.

U.S. officials said their objective is less Kobane itself — which they said still may fall to the militants — than the opportunity it presents to hit massed Islamic State forces.

“One of the reasons why you’re seeing more strikes there is because there’s more ISIL there,” Rear Adm. John F. Kirby, the Pentagon press secretary, said Wednesday, using an acronym for the Islamic State. He said that “hundreds” of militants have been killed.

But Kobane also has come to represent a potential propaganda victory the Obama administration is eager to deny the militants.

Recent U.S. airstrikes have focused heavily on the Syrian town of Kobane with 39 of the last 40 strikes in Syria occuring there.

“Part of the dynamic we want to show is that these guys aren’t ten feet tall,” said a senior administration official who spoke on the condition of anonymity to discuss the motivation for target selection beyond purely military objectives. “A lot of their edge has been psychological.”

“They’re like a shark; if they’re not swimming, they’re sinking. That’s how they recruit foreign fighters and establish themselves as the vanguard of global jihad,” the official said.

The militant siege of Kobane, the official acknowledged, has become the subject of “acute media attention,” with news cameras just across the border in Turkey transmitting live images of combat. The United Nations last week warned of a “genocide” if the militants are allowed to take over. French President François Hollande — whose government is participating in coalition activities in Iraq but not in Syria — this week called on all nations to do their utmost to help save the town.

This week, the dominant image has been of U.S. airstrikes. “I don’t want to suggest that our military actions are driven by the simple fact that this is a town that can be seen by cameras,” the senior official said. “I do think it’s fair to say that we have an interest in blunting their momentum to show that they are not this inevitably advancing force that they have portrayed themselves as being.”

A senior Defense Department official acknowledged the town’s propaganda value to the Islamic State but insisted that “we are not dropping bombs on them to make them look weak. We are dropping bombs on them to make them weak.”

There were sharply differing assessments Wednesday of the effect of the airstrikes. “Right now, we believe it’s still being defended and still in their hands,” Kirby said of the Syrian Kurdish fighters in the town. But Kobane, he said, “could very well still fall.”

Other U.S. military officials, with access to real-time intelligence assessments, said the militants have continued to pour in resources and remain in control of a significant portion of the town.

Kurdish fighters and activists on the ground said that two days of relentless attacks have turned the tide in their favor.

Ihsan Naasan, the deputy foreign minister of Kobane’s self-proclaimed government, said Kurdish defenders had pushed the jihadists back more than four miles from the western edge of the town by nightfall Wednesday and were advancing into the eastern and southern neighborhoods of the city.

He claimed that Kurdish fighters with the People’s Protection Units, or YPG, now control 80 percent of Kobane after losing more than half of it in heavy fighting in past days.

“The YPG now have the initiative,” Naasan said, speaking from inside the town. “They are on the counteroffensive against the Islamic State.”

If the Kurdish fighters manage to retake Kobane, it would be the first time that U.S. strikes have helped eject the Islamic State from territory in Syria since the air war was expanded to include the northern and eastern parts of the country a little over three weeks ago.

The border town, nestled amid rolling farmland in a remote part of north-central Syria, has limited strategic significance. Islamic State fighters had advanced toward it unimpeded, capturing scores of tiny villages across a large swath of territory along the way and sending more than 200,000 people fleeing in panic into Turkish territory.

Although daily U.S. airstrikes had begun in Kobane over a week earlier, it was only on Tuesday, as militant reinforcements were said to have arrived, that coalition sorties sharply escalated. On Wednesday, the U.S. Central Command said it had carried out 18 strikes in the previous 24 hours, on top of 21 reported the previous day.

Ground-shaking explosions reverberated repeatedly across the countryside spanning the Syria-Turkey border Wednesday, sending plumes of smoke billowing from the town. Kurdish activists said that the bodies of “tens” of Islamic State fighters lay strewn around the streets of bombed neighborhoods that they said were subsequently retaken by defenders.

The Islamic State, which typically boasts about its conquests in videos and statements on social media, has fallen silent on the Kobane battle, amid unconfirmed reports that some of its more senior commanders have been killed. Among those mentioned are leaders known as Abu Khattab al-Kurdi, from the town of Halabja in Iraq’s Kurdish region, and Abu Mohammed al-Amriki, a Chechen who was said to have lived in the United States for a decade before leaving to fight in Syria.

The intensified effort has put the United States in the curious position of bombing to defend a Kurdish faction aligned in opposition to its usual regional allies. The Kurdish YPG militia defending the town is affiliated with the Kurdistan Workers’ Party, or PKK, which in the past has waged a bloody insurgency against Turkey and is designated as a terrorist organization by both Turkey and the United States.

The group is also at odds with Washington’s long-standing Kurdish allies in Iraq and its Syrian affiliates, which accuse the Syrian Kurdish faction of working on behalf of Syrian President Bashar al-Assad, a charge the group denies.

Kurdish officials say the YPG has been unofficially cooperating with the United States, delivering the coordinates of Islamic State positions to coalition officials in Iraqi Kurdistan’s capital, Irbil. Kirby, at the Pentagon, declined to comment on the reports.

Turkey has refused to allow supplies across the border to the YPG, a situation the Obama administration would like to reverse. U.S. diplomats, and a Pentagon planning team coordinating Turkey’s contribution to the anti-Islamic State coalition, have asked the Turks to put aside their antipathy toward the Kurds and allow the fighters free access to regroup and resupply themselves on the other side of the border.

Retired Gen. John Allen, the administration’s coordinator for the coalition who last week visited Turkey, said Wednesday that the goal of the airstrikes was to provide “white space” for the defenders and to “give some time to the fighters to organize on the ground.”

Sly reported from Sanliurfa, Turkey.