Afghan President Hamid Karzai Wednesday congratulated US President Barack Obama on his re-election, saying he hoped it would lead to an expansion of relations between the two countries.

"The president of Afghanistan hopes that with President Obama's re-election relations between Afghanistan and the United States, based on bilateral interests, are further expanded," his spokesman Aimal Faizi told AFP.

The US has some 68,000 troops in Afghanistan helping Karzai's government fight a Taliban insurgency.