Obama visits AfghanistanThe US President Barack Obama on Sunday made a surprise visit to Afghanistan to see the US troops stationed in the country.

Obama is expected to spend a few hours at the main US base in Afghanistan – Bagram air field.

It is yet not clear if President Obama will have a meeting with President Hamid Karzai during his visit to Afghanistan.

According to reports, President Obama has made the surprise Memorial Day weekend visit to to thank forces who are preparing to withdraw after nearly 13 years of war.

The visit by Obama comes as Afghanistan goes through a critical period of political and security transition.

Obama is considering to leave a small number of US troops in Afghanistan beyond 2014 to train Afghan security forces and carry out anti-terror operations.

However, the presence of US forces in Afghanistan beyond 2014 would be subject to the signing of the bilateral security agreement between Kabul and Washington.

President Hamid Karzai has so far refused to sign the bilateral security agreement between the two nations despite the draft agreement was endorsed during the consultative Loya Jirga last year.