Across the globe, news of the terrorist attacks in Paris brought reactions of horror and anger, and many government leaders called for stepped-up efforts to counter extremists.

The Islamic State group's announcement that its members carried out the Friday-night massacre brought immediate condemnation.

From the White House, President Barack Obama said the United States is ready to help France in any way possible, and he condemned the coordinated attacks in Paris as an "outrageous attempt to terrorize civilians." Vice President Joe Biden said "such savagery can never threaten who we are."

'Medieval and modern fascism'

U.S. Secretary of State John Kerry said the bloodshed in Paris and other recent acts of terror are "a kind of medieval and modern fascism at the same time, which has no regard for life, which seeks to destroy and create chaos and disorder and fear."

Kerry was speaking in Vienna alongside Russian Foreign Minister Sergei Lavrov, where both are attending international talks on the Syrian civil war.

Lavrov said there will be no tolerance for terrorists. "There will be no justification for us not doing much more to defeat" the Islamic State and other terror groups, he said.

Sergei Naryshkin, speaker of the State Duma, lower
Sergei Naryshkin, speaker of the State Duma, lower parliament chamber, lays flowers in front of the French consulate in St.Petersburg, Russia,for the victims of the Paris attacks on Friday, Nov. 14, 2015.

In London, Prime Minister David Cameron denounced the IS militants as "brutal and callous murderers," and said Britain will redouble its efforts to wipe out "this poisonous, extremist ideology."

Cameron spoke after an emergency Cabinet meeting that pledged support for France. He said he expected a number of British casualties in Paris but said the Islamic State group will eventually be defeated.

In Vatican City, Pope Francis expressed his profound distress and said "there cannot be justification, religious or human" for such attacks.

'Barbaric' incidents

Indian Prime Minister Narendra Modi condemned the "barbaric" incidents in Paris in the strongest terms: "More than 100 people lost their lives while they were doing what they love or spending time with their loved ones."

U.N. Secretary-General Ban Ki-moon condemned what he called the "despicable terrorist attacks."

In a letter to French President Francois Hollande, European Council President Donald Tusk said, "We will ensure that the tragic, shameful act of terrorism against Paris fails in its purpose: to divide, to frighten and to undermine liberty, equality and fraternity – the values that make France a great nation."