Afghanistan's president has said he would sign a long-awaited deal with Washington, allowing US-led troops to stay in the country after 2014, but only after the end of the year.

Hamid Karzai told Radio Free Europe in an interview broadcast on Wednesday that he would ink the security agreement in 2014 if the United States meets demands to not raid Afghan homes and help restart peace talks with the Taliban.

The move seemed to show that Karzai stepped back on his demand that the US guarantee free and fair presidential elections on April 5, following assurances he received during a Monday meeting with Susan Rice, US National Security Adviser.

However, the White House said Karzai had outlined new conditions in the meeting with Rice and "indicated he is not prepared to sign it promptly".

"Without a prompt signature, the US would have no choice but to initiate planning for a post-2014 future in which there would be no US or NATO troop presence in Afghanistan," a White House statement quoted Rice as saying.

Loya Jirga's decision

On Sunday, an assembly of Afghan elders, known as the Loya Jirga, endorsed the security pact, but Karzai suggested he might not sign it until after national elections next spring.

Karzai's defiance has surprised the many who had attended the Loya Jirga, which he had proclaimed would have the final word on the security deal.

US officials, including Secretary of State John Kerry and Defense Secretary Chuck Hagel, have said the bilateral security deal with Afghanistan must be signed by year-end to begin preparations for a post-2014 presence.

The Bilateral Security Agreement (BSA) includes a provision allowing raids in exceptional circumstances - when an American life is directly under threat - but it would not take effect until 2015.

This issue is particularly sensitive among Afghans after a dozen years of war between Afghan and foreign forces and Taliban fighters.

US and other foreign troops have been in Afghanistan since the ousting of the Taliban regime by US-backed Afghan forces in late 2001.

Source: Agencies