Last year saw the bloodiest violence since the militants' ousting by U.S.-led forces in 2001.

But the initiatives ran aground, and the last nine months have seen some of the conflict's bloodiest violence.

Taliban fighters staged a surprise comeback last year with the bloodiest violence since U.S.-led troops forced them from power in 2001.

Concern has mounted over Taliban sanctuaries in Pakistan, from where the Islamist militants last year orchestrated the bloodiest violence in neighbouring Afghanistan since 2001.

On Wednesday, a wave of bombings killed more than 75 people across Iraq in the bloodiest violence since U.S. troops left the country in December.

Conflict has been worsening in Afghanistan, with more than 5,000 people killed in the past 17 months, the bloodiest violence since the Taliban's ouster.