US President Barack Obama [Images] on Tuesday gave no indication of early withdrawal of US troops from war-torn Afghanistan, which he described as a "big challenge".

He also attacked the Hamid Karzai [Images] Government in Afghanistan, saying it appears to be "detached" from what is going on in the region.

Obama, also the Commander-in-Chief of the US Armed Forces, did not specify when he will withdraw his forces from the Al Qaeda [Images] and Taliban-infested country.

Responding to a question on Afghanistan during his maiden press conference at the White House, Obama said it is because of the extraordinary work done by US troops and some very good diplomatic work done by the US Ambassador [Images] there, Iraq recently had peaceful elections.

"One got a sense that the political system is now functioning in a meaningful way. You do not see that yet in Afghanistan," he said.

"They've got elections coming up, but effectively the national government (led by Hamid Karzai) seems very detached from what's going on in the surrounding community," Obama said, clearly expressing his displeasure over the functioning of the Afghan President, considered close to former President George W Bush [Images].
 
During his election campaign, Obama had come down heavily on the Karzai government, saying that the Afghan President's authority does not run beyond the capital Kabul.

"In addition, you have got the Taliban [Images] and Al Qaeda operating in the FATA and these border regions between Afghanistan and Pakistan. And what we haven't seen is the kind of concerted effort to root out those safe havens that would ultimately make our mission successful," Obama said.

He said the US cannot allow Al Qaeda to operate from Afghanistan and safe havens.

"My bottom line is that we cannot allow Al Qaeda to operate. We cannot have those safe havens in that region. And we're going to have to work both smartly and effectively, but with consistency in order to make sure that those safe havens do not exist," the President said.

Obama plans to send a further 30,000 troops to Afghanistan, doubling the US contingent fighting Taliban-led insurgency along with NATO forces.