The chief of US Federal Bureau of Investigation (FBI) James Comey said on Wednesday the number of American recruits who has gone or attempted to travel to Syria to join ISIS was more than 200.
"We continue to identify individuals who seek to join the ranks of foreign fighters... and also homegrown violent extremists who may aspire to attack the United States from within," Comey told US lawmakers on the Senate Select Committee on Intelligence.
The US has been combatting ISIS since the militant group seized Mosul in June 2014 and Washington pioneered an aerial campaign against militants in both Iraq and Syria from last autumn onwards.
The FBI tightened its security measures to prevent recruitments of US nationals by the militant group which has been using technology and communication facilities through internet, most notably social media sites, in order to lure young Americans.
The FBI chief warned that the ISIS-like terror groups have been using some encrypted programmes to prevent law enforcement officials from accessing their communications with recruits inside the US.
Comey urged technology companies to cooperate with both FBI and NSA authorities by allowing to access to encrypted communications made by the suspected ISIS sympathisers for the sake of America’s fighting against the militant group.
He pointed out the power of social media in terms of militant recruitment as he emphasised that ISIS had currently 21,000 English-language followers on Twitter which has constituted a fertile ground to get attraction from teen Americans.
ISIS gets an overwhelming majority of its human resources from countries in the West despite the US and the EU have voiced up discontent with the issue.
The chief of EU’s counter-terrorism unit Gilles de Kerchove told a European Parliament committee last month that the number of European recruitments who joined ISIS and similar groups has so far remained stable in Europe.
Kerchove said the EU countries were unsuccessful so far in halting militant outflow from Europe to the militant groups currently fighting in Iraq and Syria.
He stated that the numbers of recruitment who departed from the EU countries, such as Britain, Belgium, Germany and France have stabilised and unabated although the 28-member bloc has ostensibly raised its concern against the increasing militancy on its soils.
More than 4,000 militants were believed to have gone to the Middle East to join the groups like ISIS and Al Qaeda.
Since the Charlie Hebdo attack targeting France in January, the EU governments have prioritised the issue of recruitment made by the radical groups among from European nationals.
De Kerchove has admitted their failure to prevent militancy as he said, “We have not been able to stem the flow yet.”
Europe has long been struggling with the increasing militancy which started to undermine its security particularly in the wake of migrant crisis that came to the fore as one of the most important non-conventional threats in Europe’s recent security deficit.
The EU has blamed some countries in the Middle East, foremost Turkey, due to the border management and checking problems on the porous borders with Syria about the militant outflow from Europe to Turkey, and then further into the Middle East.
But the Turkish Foreign Ministry stated that the European allegations were unjust and denied the problems erupted due to its border management were part of a “propaganda” that aimed to classify the country as if it supports the militancy in Iraq and Syria.
Turkey blames the EU countries for not informing it in advance and with the lack of intelligence sharing cooperation about European nationals who are suspected of traveling to join ISIS who pass through its borders with Syria.