He also said that nothing could be said about the authenticity of an al-Qaeda video which is still under examination.
The video appears to show the troops in a good condition, at points smiling and waving at the camera.
Barack Obama said the US will continue to draw on its substantial counterterrorism capabilities to prevent ISIL attacks.
So far, those who think attrition would weaken the cults if the standoff is prolonged are being proved wrong.
IS is a Middle-East based Sunni jihadist group which has threatened to demolish all Shia shrines.
Bergen said that ISIS is more successful than Al-Qaeda in terms of getting territory, money, fighters and establishing a foothold in Middle East.
There is a threat perception from such agencies but the nation is prepared for it, he said.
Al-Qaeda leader Ayman al-Zawahri on Wednesday announced the formation of an Indian branch of his militant group.
In the video, al-Zawahiri promises the expansion of al-Qaeda operations throughout the Indian subcontinent.
This video, the first from Zawahiri this year, should be taken very seriously, said US’ top expert on counter-terrorism.
After the 2008 Mumbai terror attacks, co-operation between US and India on counter-terrorism issues has increased significantly.
Ministry officials said the IB has been asked to send a report as early as possible giving details of the video.
In a video, al Zawahri promised to spread Islamic rule and ‘raise the flag of jihad’ across the Indian subcontinent.
بسم الله الرحمن الرحيم مؤسسة السحاب للإنتاج الإعلامي تقدم: الإصدار الخاص بمناسبة وحدة صفوف المجاهدين وإنشاء ((جماعة قاعدة الجهاد في شبه القارة الهندية)) هذا الملف يحتوي على ثلاث بيانات: 1- إعلان إنشاء فرع جديد لجماعة قاعدة الجهاد في شبة القارة الهندية [عصابة تغزو الهند بإذن الله] (بيان الشيخ أيمن الظواهري حفظه الله) 2- تجديد البيعة […]
The statement said ‘the Indian Subcontinent will wage ‘jihad against America and the system of international infidels’.