Brussels, Oct 16 (IANS): NATO Secretary General Jens Stoltenberg on Thursday welcomed US President Obama's announcement on Afghanistan, saying this decision paves the way for a sustained presence by NATO Allies and partners in Afghanistan.

US President Barack Obama announced plans on Thursday to keep 5,500 US troops in Afghanistan into 2017, and to maintain the current 9,800 forces through "most of 2016."

Commending that the US will maintain its current troop levels in Afghanistan, Stoltenberg said in a statement, "The significant US contribution will be an important factor as we consider the way ahead," Xinhua reported.

He said the Alliance will take key decisions in the coming weeks about the future scope of the Resolute Support Mission, a new NATO-led mission launched on January 1 to provide further training, advice and assistance for the Afghan security forces and institutions.

"The Afghan security forces continue to carry out their security responsibilities across the country, in a very challenging environment," Stoltenberg added.

Thursday's decision mounts to a major political reversal to Obama's campaign promises that he would withdraw all but a small US embassy-based force in the capital, Kabul, before leaving office in January 2017.