French President Francois Hollande and United State President Barack Obama pledged their solidarity in the fight against the Islamic State in Iraq and Syria (ISIS), declaring to step up strikes in Syria and Iraq, but with not commitment to boots on the ground.
In an hour-long joint press conference on Tuesday, Mr Obama said: "The US and france stand united in total solidarity, to deliver justice...and defend our nations".
He added: 'We're never forgotten how the French people stood by us after 9/11 and today we stand by you."
He said the US would continue to quickly share intelligence information with France and called on European Union countries to require airlines to share passenger information.
Mr Hollande added that the two countries have "decided to scale up our strikes in Syria and Iraq, to strengthen intelligence sharing regarding the targets".
When taking questions however, Mr Hollande said France "would not act militarily on the ground".
Mr Hollande has been seeking international support for his newly declared war on the Islamic State of Iraq and Syria (ISIS) after the Paris attacks.
The meeting in Washington took place amid rising tensions between Russia and Turkey, due to Turkey's downing of a Russian warplane. Both countries are key to resolving the Syrian conflict.
The French President met with British Prime Minister David Cameron on Monday, who has pledged to press the British Parliament to approve military action in Syria and on Thursday, continues his efforts to rally support in Moscow.
Mr Hollande has called on Washington and Moscow to form a grand coalition against the ISIS, in light of both the Paris attacks and the downing of the Russian plane over Sinai.
But so far, the US has made it quite clear that working with Russia would be difficult if the two nations continue to bat for different teams.
Russia supports Syrian president President Bashar Al-Assad, while the US believes he must be removed and supports the Kurds instead.
Mr Obama said: "Russia's strikes against the moderate opposition only bolster the Assad regime."
And added that "Russia could play a more constructive role if shift its focus" to fighting ISIS.
The United Nations Security Council passed a France-sponsored resolution Friday, sending a message from world powers to the international community to "redouble and coordinate" programmes to suppress terrorist acts by "all necessary measures".
Said Mr Hollande: "We have a resolution from the secuirty council, we must take action against Daesh.
"I will ask President Putin, that the strikes must be against Daesh, against Terrorism. Those threatening us are threatening the Russia, we must coordinate ourselves."
By the end of the week, Mr Hollande will have met other world leaders from Germany, Italy, Canada and China. At stake are French regional elections in two weeks, and the presidential primaries next year, which are pushing Mr Hollande to demonstrate his influence and leadership in the fight against ISIS.
Meanwhile, the US on Tuesday also announced a worldwide travel alert for its citizens.
"Current information suggests that ISIL (another acronym for ISIS), Al-Qaeda, Boko Haram and other terrorist groups continue to plan terrorist attacks in multiple regions," said a State Department travel advisory.