Barack Obama has called for world leaders to join him at a climate summit in Paris later this month.
The call comes after the terrorist attacks in the city that left 130 people last Friday.
The attacks have led to increased security in the French capital, and the country's government has extended a state of emergency for three months.
In neighbouring Belgium this weekend, the terror alert in Brussels has been raised to its highest possible level, with authorities saying there is a "serious and imminent threat".
Speaking from Kuala Lumpur earlier today, the US president called on world leaders to show resolve and attend the planned summit despite the attacks and threats.
"It's absolutely vital for every country, every leader, to send a signal that the viciousness of a handful of killers does not stop the world from doing vital business," President Obama said.
He said it is important to show that "one of the most beautiful, enticing cities in the world, is not going to be cowered by the violent, demented actions of a few".
More than 120 world leaders have said they will attend the United Nations climate change conference - known as COP21 - which is due to get underway on November 30th.
Meanwhile British politicians will get to vote again on whether Britain can proceed with airstrikes on Islamic State in Syria - but not until their government is "confident" of getting a majority.
Chancellor George Osborne said losing such a vote for a second time - after a previous defeat in 2013 - would be a "publicity coup" for the extremist group.
On Monday, David Cameron is meeting French President Francois Hollande for talks on how to tackle IS in Iraq and Syria.
This gathering follows the unanimous UN backing of France's call to co-ordinate international efforts in the wake of the Paris attacks.
France is part of a US-led coalition which has been carrying out airstrikes against IS for over a year, while Russia launched a separate bombing campaign in September.
UN Secretary General Ban Ki-moon urged Russia and the US on Sunday to co-operate in their efforts to root out terrorism, while President Obama said the US and its allies would "not relent" in its efforts to "destroy" IS.
