(AP) Pledging solidarity after the Paris attacks, President Barack Obama promised Tuesday to work with France and other allies to intensify the U.S.-led campaign against the Islamic State, saying America will not be cowed by the scourge of terrorism.

"We cannot succumb to fear," Obama said, standing alongside French President Francois Hollande after they met at the White House to discuss the anti-ISIS mission. "Make no mistake, we will win, and groups like ISIL will lose."

Hollande's trip to Washington was part of a diplomatic push to get the U.S. and other nations to bolster efforts to destroy the militant group that has claimed responsibility for the Paris attacks. The French president planned to urge Obama to work with Russia to build a new coalition to fight the extremists.

But Hollande's mission quickly became entangled with the fallout from a Russian military plane downed by Turkey - an incident with echoes of the Cold War. The shootdown underscored what some see as a need for better coordination among the sprawling cast of interests engaged on the battlefields and in the skies above Iraq and Syria. At the same time, conflicting accounts and rising tensions stood to make any closer contact between interests more difficult.

Even before the incident between Turkey and Russia, Hollande faced a tough challenge in getting Obama to agree to a partnership with Moscow. The U.S. is deeply skeptical of President Vladimir Putin's motivations, given his longstanding support for Syrian President Bashar Assad.

U.S. forces were not involved in the air incident, according to an American military official, who was not authorized to discuss the incident publicly and so spoke on condition of anonymity.

Nearly five years of clashes between Assad's government and rebel forces have created a vacuum that has allowed the Islamic State to thrive. The group appears to now be focusing on targets outside its base in Syria and Iraq, including attacks in Lebanon and Turkey and the downing of a Russian airliner over Egypt.

Given the rash of attacks, Obama is now facing increased pressure at home and abroad to ramp up U.S. efforts to destroy the militants. So far, Obama is resisting calls to significantly escalate his approach, and instead is focused on getting other countries to offer more counterintelligence, humanitarian and military assistance.

"The United States is certainly pulling more than our own weight," White House spokesman Josh Earnest said Monday. "And we believe that there is more that can be done if countries are willing to contribute additional resources."

The U.S. campaign has centered largely on airstrikes as well as the training and assisting of security forces on the ground in Iraq. Efforts to train and equip moderate rebel groups in Syria have struggled, and Obama has authorized the deployment of 50 special operations forces to the country to jumpstart the program.

France has stepped up its airstrikes following the Paris attacks, relying in part on U.S. intelligence to hit targets in Raqqa, the Islamic State group's stronghold in Syria. British Prime Minister David Cameron said on Monday he would seek parliamentary approval this week for Britain to begin airstrikes as well.

Hollande wants the U.S.-led coalition to start cooperating with Russia, which is also launching airstrikes in Syria. While Putin says his country is targeting the Islamic State militants, the U.S. contends Moscow is going after rebels fighting Assad, a Kremlin ally whom the U.S. wants pushed out.

Last week, Hollande called for the U.S. and Russia to set aside their policy divisions over Syria and "fight this terrorist army in a broad, single coalition." But his office acknowledges that "coordination" sounds like a far more realistic goal.

"We are not talking about a command center. We are talking about coordination of methods and exchange of intelligence," a French diplomat said on Monday. The diplomat wasn't authorized to publicly discuss the subject and spoke on condition of anonymity.

Earnest said the U.S. would "continue the conversation" with Putin but suggested Obama would make no promises to Hollande during Tuesday's visit.

Hollande is slated to travel to Moscow later in the week for meetings with Putin.

Beyond their discussions on military cooperation, Obama and Hollande were expected to discuss diplomatic efforts to achieve a political transition in Syria.

While Russia is backing a new diplomatic effort in Syria, Moscow still refuses to support steps that explicitly call for removing Assad.

The quagmire in Syria has dragged on for nearly five years, and criticism of Obama's strategy appears only to grow louder.