US President Barack Obama has told Afghanistan's president, Hamid Karzai, that he must make a more concerted effort to end corruption in Afghanistan's government.

Mr Obama has also emphasised the time has come for the Afghan government to prepare to ultimately defend itself.

From the White House, he said he expects more diligent efforts to end corruption, an acceleration in the training of Afghan security forces and obvious benefits for Afghan people.

While Mr Obama is about to decide on whether to bolster current US troop strength in Afghanistan, he has been under increasing pressure from Congress and the public to do something about what they see as an untrustworthy partner.

Karzai has led Afghanistan since US forces entered the country in 2001.

He won an election in 2004.

His latest victory will give him another five-year mandate.