President Obama used a press conference Tuesday at the Paris climate summit to once again claim progress in the U.S.-led coalition’s campaign against the Islamic State, while also setting low near-term expectations for gaining Russian President Vladimir Putin's full cooperation in the fight.

The president, speaking before he departs the climate summit to return to Washington, said “it is possible” over the next several months that there will be "a shift in calculation in the Russians and a recognition that it's time to bring the civil war in Syria to a close."

But he quickly tempered that prediction by acknowledging Russia is hitting Syrian opposition targets, some of whom are supported by the U.S.

“I don’t expect you’re going to see a 180 turn on their strategy over the next several weeks,” Obama said.

The president said the U.S. shouldn’t be under any “illusions” that Russia will start “hitting only ISIL targets.”

Obama said that wasn’t happening before, and, “It’s not going to be happening in the next several weeks.”

The comments demonstrate the potentially slow and plodding path ahead toward resolving the Syrian civil war.

While Russia opposes the Islamic State – which claimed credit for bringing down a Russian flight over Egypt – Moscow also supports Syrian leader Bashar al-Assad.

Obama, though, reiterated that the civil war cannot come to an end while Assad remains in power

Obama suggested his hope is that diplomatic talks in Vienna result in a gradual change, including “pockets of cease-fires in and around Syria.”

This, he said, could bring about a “conversation about politics.”

Still, he conceded the extremist threat that has wrought fear across the Middle East and the West would not be eliminated in the short term.

"ISIL is going to continue to be a deadly organization because of its social media, the resources it has and the networks of experienced fighters that it possesses," Obama said, using one of several acronyms for the extremist group. "It's going to continue to be a serious threat for some time to come."

Concerns about ISIS have overshadowed Obama's two-day trip to Paris, where ISIS-linked attacks killed 130 people last month in the run-up to the climate negotiations. Obama had sought to turn the outrage over the Paris attacks and the group's shoot-down of a Russian passenger jet in Egypt into new resolve for stepping up the fight against ISIS.

Yet those hopes have been dampened by the spiraling diplomatic crisis between Turkey and Russia, sparked late last month when Turkey shot down a Russian warplane it said had violated its airspace along the border with Syria. The U.S. sees both Russia and Turkey as critical to resolving the Syria crisis.

Aiming to head off a rift between the two major Mideast players, Obama urged both to "de-escalate" their conflict and not get distracted from the campaign against ISIS. Yet in a meeting with Turkish President Recep Tayyip Erdogan, Obama also vouched for the NATO ally's right to self-defense, and he pledged a solid U.S. commitment "to Turkey's security and its sovereignty."

Sitting down with Erdogan on the sidelines of climate talks, Obama said the U.S. was very interested in accelerating its military relationship with Turkey. He also praised Turkey for generously accepting refugees fleeing violence in Syria, and credited Turkey with strengthening security along its border.

Turkey, too, hopes to avoid tensions with Russia, Erdogan told reporters as he and Obama finished their roughly hour-long meeting. 

The Associated Press contributed to this report.