US President Barack Obama has abandoned plans to cut the number of US troops in Afghanistan to 5,500 by the end of this year. Instead, he now says 8,400 troops will remain there until the end of his administration in 2017. That will be a reduction of 1,400 from the 9,800 who are currently in Afghanistan.

Speaking from the White House, Obama said the decision was necessary because security in Afghanistan remained precarious and Taliban forces had gained ground in some places. He said the US forces would remain to support Afghan forces and pursue terrorists.

CCTV's Jessica Stone brings us more from the White House. Fresh off the burials of 27 Afghan police recruits in a Taliban bus attack. U.S. President Barack Obama announces another troop adjustment for the American military commitment in Afghanistan.

"Instead of going down to 5,500 troops by the end of this year, the United States will maintain approximately 8,400 troops in Afghanistan into next year, through the end of my administration," said Obama.

For a president who promised to end this war, stabilizing Afghanistan has proved to be a hard puzzle to solve. Obama has repeatedly adjusted the number and role of U.S. troops during the nearly 15 year- old war.

During his presidency, Obama has both increased and drawn down troops, while seeking to eliminate Afghanistan as a sanctuary for terrorists.

"If these terrorists succeed in regaining areas and camps where they can train and plot, they will attempt more attacks against us. We cannot allow that to happen," said Obama.

NATO and U.S. troops have two roles in Afghanistan: counter-terrorism and training- and-advising Afghan security forces. After a summer spike in violence, the Pentagon has now expanded the military's authority to call in airstrikes and participate in limited combat.

Yet, senior administration officials say they're encouraged - that Pakistan's army chief is cracking down on illegal border crossings to Afghanistan. Though reconciliation talks with China, Pakistan, Afghanistan and the Taliban have so-far not resumed.

The troop announcement comes just days before NATO members meet in Warsaw, Poland. On the agenda: the way forward with troop commitments in Afghanistan.