Dozens of Nations at U.S. Summit on Violent Extremism

Reeling from a string of bloody terror attacks from Denmark to Libya, representatives from 60 countries will gather from Tuesday for a White House summit on combating violent extremism.

The three-day meeting hosted by President Barack Obama has been in the pipeline for months, but has been given deeper significance in the wake of several similarly inspired attacks.

On Sunday, a video emerged apparently showing Islamic State jihadists beheading 21 Egyptian Christians in Libya.

Also over the weekend, attacks on a cultural center and a synagogue in Copenhagen left two people dead.

Both came just weeks after the Paris attacks by Islamist gunmen on the Charlie Hebdo satirical weekly and a kosher supermarket that left 17 people dead.

Senior U.S. officials said the White House summit would look at ways to combat those "inspiring, radicalizing, financing or recruiting individuals or groups" to commit violent extremism.

Information sharing, countering "violent extremist narratives" via social media and judging the effectiveness of these strategies would all be discussed.

Obama is expected to speak on Wednesday and Thursday.

- 'Islamic' vs 'violent' extremism - 

The White House has been criticized for not specifically focusing the meeting on combating "Islamic extremism" or broader military efforts to tackle the Islamic State and other groups.

Obama's Republican political foes say his avoidance of terms like "Islamic extremism" is little more than political correctness.

His administration stress that the attacks have "absolutely no justification" in any religion. 

"We are very, very clear that we do not believe that they are representing Islam," said one senior US official. 

"So you can call them what you want. We're calling them terrorists."

Tuesday and Wednesday will focus on the domestic U.S. effort to counter extremism, with Vice President Joe Biden holding a discussion on pilot anti-extremist programs in Boston, Minneapolis–Saint Paul and greater Los Angeles.

They will "talk about what's working, what's not working, and to share ideas with one another and with some of their international counterparts," said a senior US official.

"Our approach empowers communities to push back against violent extremists," said the official, describing the approach as an "incredibly important element of our counterterrorism and national security toolkit."

On Wednesday, the private sector, non-governmental groups and cities around the world will join the meeting.

"This is about building a comprehensive network to fight back against violent extremism," said a senior administration official.

On Thursday, international efforts will take center stage, with Secretary of State John Kerry kicking off proceedings.

Britain's home secretary, the United Arab Emirates minister of states and foreign affairs and a religious scholar from Syria are among others due to speak.