During a joint news conference with French President Francois Hollande, President Obama reassured the public that the Islamic State will be defeated. Addressing the American public directly, Obama said, "We cannot and will not succumb to fear, nor can we allow fear to divide us." (Associated Press)

President Obama urged Russia and NATO allies Tuesday to “discourage any escalation” after a Russian warplane was downed along Turkey’s border with Syria.

Russian President Vladmir Putin denounced the incident as a “stab in the back,” and it could significantly hinder Western efforts to enlist Moscow in battling the Islamic State terrorist group and seeking a resolution to Syria’s nearly five-year civil war.

“Turkey, like every country, has the right to defend its territory and its airspace,” Obama said during a joint news conference in Washington with French President François Hollande. But Obama called on all sides to “take measures to discourage any escalation.”

The leaders’ talks focused on recent attacks in Paris and the broader strategies against the Islamic State. The administration is pressing for Hollande to mobilize other European nations to do more in the wake of the attacks that killed 130 people in the French capital on Nov. 13, even as Russia remains an unpredictable player in the battle against the extremist fighters.

French President François Hollande walks down the stairs from his plane upon his arrival at Andrews Air Force Base in Maryland on Tuesday. (Jose Luis Magana/Associated Press)

Obama did not say whether intelligence reports supported claims by NATO-member Turkey that the Russian fighter crossed into Turkish airspace. He said, however, that it underscored the risks of Russia’s military operations near the Turkish border.

A U.S.-led coalition also is conducting airstrikes against Islamic State targets in Syria and Iraq, raising further fears of potential inadvertent conflicts from the overlapping air campaigns.

Russia has been launching airstrikes in support of a key ally, Syria, and its president, Bashar al-Assad. But many Russian attacks also have hit anti-Assad rebels, including some factions backed by Turkey and its Western allies.

After meeting with Hollande at the White House, Obama declared “total solidarity” with France, saying his planned trip to Paris next week for a climate change summit is a “powerful rebuke” to terrorism.

“We cannot succumb to fear,” he said.

In a jab at U.S. politicians raising questions about accepting Syrian refugees, Obama praised France’s decision to allow entry to tens of thousands of Syrians fleeing warfare and the Islamic State.

“We will not allow those who want to destroy what we have built. . . . We need a joint response,” said Hollande, who is holding a series of high-level meetings seeking to strengthen military and diplomatic pressure on the Islamic State.

Hollande vowed to intensify France’s airstrikes in Syria, citing Islamic State supply lines and command centers as top targets. But he noted that he does not plan to send ground forces to Syria.

“The Paris attacks generated a lot of emotion, but that’s not enough,” Hollande said, adding that he appreciates the compassion others have expressed. “But we must act.”

Speaking to reporters after the news conference, Vice President Biden said that he is optimistic that Russia will “tamp it down” when it comes to the conflict with Turkey and that several European nations will be more willing to escalate their efforts to combat the Islamic State, given the threat of another attack on European soil.

“This is one of those God-awful events that I think may bring . . . an awful lot of parties to their senses and what’s in their primary interest. A lot of people have secondary interests, but their primary interest is Daesh,” he said, using another name for the Islamic State.

“My guess is — Hollande did not say this — my guess is the Europeans are going to focus a little more on the help Turkey may need,” Biden said, adding that when it comes to Syrian refugees, “everybody says, ‘Turkey, keep them.’ Well, that’s a lot of folks. That’s a lot of money.”

Hollande’s trip to Washington, just 11 days after terrorists allied with the Islamic State launched six attacks in Paris, comes as the French president is jetting to several world capitals to strengthen the military and covert intelligence response to militants based in Syria and Iraq.

On Monday, Hollande toured the deadliest site of this month’s attacks, the Bataclan theater, with British Prime Minister David Cameron. Later this week, the French president will meet with the leaders of Germany, Italy and Russia.

Speaking to reporters Monday, White House press secretary Josh Earnest declined to discuss in detail how the international approach to push back the Islamic State, also known as ISIS and ISIL, might change. But said he “wouldn’t downplay the significance of additional expressions of solidarity and support” on a nation that is reeling from a devastating loss.

“This is a nation that’s concerned about the security situation inside their country,” he said. “And they can and should take a lot of solace in knowing the most powerful country in the world has their back and is standing with them in this difficult time.”

He noted that French airstrikes carried out over Syria last week were based on targets that were identified using U.S. intelligence and were backed up by an American search-and-rescue team in case the strikes went awry.

While Hollande is working to coordinate more closely with Russia, this new overture is likely to create some friction with administration officials.

Earnest said that if “Russia is prepared to commit the kinds of resources that the United States has in a way that’s integrated with the international community to defeating ISIL, we’d welcome that contribution,” but he expressed deep skepticism about whether that would happen.