DOHA (Reuters) - U.S. President Barack Obama's envoy charged with building the coalition against the Islamic State said on Wednesday the growth of the group had global implications and if unchecked its militants could "wreak havoc on the progress of humanity".
Retired Gen. John Allen told a conference in Qatar the group was not merely an Iraqi problem or a Syrian problem but "a regional problem trending towards global implications".
It was critical all anti-Islamic State forces in Iraq fell under Iraqi government authority. The task of countering foreign fighter flows could not rest with Turkey alone. Turkey's borders with Syria and Iraq were the "last line of defence", he said.
(Reporting by Amena Bakr and Sami Aboudi, Editing by William Maclean)