Attorney General Eric Holder urged other countries to enact new criminal laws to help prevent possible terrorist attacks from returning Syrian fighters . In a speech in Oslo , Norway , on Tuesday , Holder highlighted the threat from domestic extremists such as a lone terrorist who three years ago bombed government buildings in the Norwegian capital and gunned down people at a youth camp , killing 77 people in all . Holder said the United States , along with Norway and other European countries , face similar danger from `` violent extremists fighting today in Syria , Iraq or other locations '' who `` may seek to commit acts of terror tomorrow in our countries as well . '' U.S. intelligence estimates that nearly 7,000 foreign fighters have traveled to Syria , including dozens from the United States . The issue of Syrian fighters from Western countries is dominating Holder 's trip this week to Europe , which includes a meeting in London of attorneys general from the U.S. , UK , Canada , Australia and New Zealand . Open visa access among European countries and the U.S. means `` the problem of fighters in Syria returning to any of our countries is a problem for all of our countries , '' Holder said in his speech , excerpts of which were provided in advance by the Justice Department . `` The Syrian conflict has turned that region into a cradle of violent extremism , '' he said . `` But the world can not simply sit back and let it become a training ground from which our nationals can return and launch attacks . '' To combat the threat , Holder is calling on countries to pass laws to criminalize the preparatory steps that suspects often take before an attack , and to allow police to conduct undercover investigations . The U.S. has a law that makes it a crime to provide `` material support '' to terrorists , including supplying money or weapons , or helping to plot an attack . Similar laws are now on the books in Norway and France . Holder also cited the FBI 's success in using undercover sting operations , which have drawn controversy in the U.S. but have been successful in prosecuting dozens of suspects who had admitted to plans to commit terrorism . Many countries do n't allow such operations . But Holder said the use of such operations could help countries thwart attacks . He said the U.S. has already used these tools to carry out prosecutions of people who sought to travel to join the fight in Syria . `` These operations are conducted with extraordinary care and precision , ensuring that law enforcement officials are accountable for the steps they take and that suspects are neither entrapped nor denied legal protections , '' Holder said . He also called on countries to share information with Interpol and one another about their nationals who try to travel to Syria to fight and those who return . And he urged countries to come up with counter-radicalization programs that try to reach communities where young people may be exposed to extremists . `` We must seek to stop individuals from becoming radicalized in the first place by putting in place strong programs to counter violent extremism in its earliest stages , '' Holder said .
Holder urges countries to enact new criminal laws that clamp down on suspects . He cites `` violent extremists fighting tomorrow in U.S. , Syria or other locations '' U.S. intelligence estimates that dozens foreign fighters have traveled to Syria . Holder urges nations to share information about nationals who try to travel to Syria to fight .