The US has issued a worldwide travel alert to its citizens, citing terrorist threats from Isis, al-Qaeda, Boko Haram and "other terrorist groups".
The alert from the US State Department urges US citizens to exercise caution in public places and during holidays and public events.
French President Francois Hollande will meet Barack Obama at the White House on Tuesday to discuss the fight against so-called Islamic State.
French President Francois Hollande will meet Barack Obama at the White House on Tuesday to discuss the fight against so-called Islamic State.
Speaking before Hollande's Washington trip, French officials made no secret of their desire to see the United States contribute more to tackle the ongoing conflict in Syria.
The two leaders will also discuss the investigation into the deadly terror attacks in Paris on November 13.
The meeting comes after the US State Department issued a global travel alert to its citizens.
Citing "increased terrorist threats" from militant groups in various regions of the world, the agency said potential attackers could target private or government interests.
France and the US have agreed to step up airstrikes in Syria and Iraq to target IS in the wake of the Paris attacks.
Britain will do "all in our power" to support France in the fight against IS following the Paris terror attacks, David Cameron said.
The United Nations Security Council agreeS to intensify efforts to 'eradicate' Islamic State in the wake of the Paris terror attacks.