NATO's plans to retain military bases in Afghanistan after its combat troops withdraw by the end of 2014 are "controversial," Russia's Foreign Minister Sergey Lavrov has declared.

"We cannot ignore how the situation in this country is unfolding, especially in light of controversial statements that foreign troops will leave in 2014 but the bases will remain," Sergei Lavrov said at an international ministerial meeting in Kazakhstan, as cited by RIA Novosti.

"We need clarity here: if the anti-terrorist mission is complete (and this is still in doubt), then are the bases being kept for some other purpose?" Lavrov said. It was not clear to what plans exactly Lavrov referred.

US President Barack Obama and Afghan President Hamid Karzai signed a long-term partnership agreement in May 2012 which set the conditions of an American withdrawal from the war-torn nation.

The deal envisages that a number of US personnel will remain in the country beyond 2014 working as military advisers and counterterrorism forces.

But Obama said Washington was not seeking permanent bases in Afghanistan.

"We will not build permanent bases in this country, nor will we be patrolling its cities and mountains," Obama said in May. "That will be the job of the Afghan people."