KABUL - US Secretary of State Hillary Clinton said on Thursday she was looking for a "reality check" on her visit to Afghanistan, but said she had seen progress, and remained hopeful about the prospects for a peaceful and stable future.

"I'm here to have a reality check," Clinton said at a meeting at the US embassy in Kabul with a group of Afghan activists from women's groups, political parties and media organisations.

"The changes that I have seen in Afghanistan are very encouraging but they must be made permanent and that can only happen if there is a consensus within the country about what kind of future you are seeking."

Clinton's arrival on Wednesday on an unannounced visit to Kabul followed several high-profile attacks in the Afghan capital, including an assault on the US embassy in September and days later the assassination of President Hamid Karzai's top peace envoy, former President Burhanuddin Rabbani.

The visit comes at a time of strains in relationships between Afghanistan, Pakistan and the United States, complicating the outlook as the Obama administration pushes ahead with plans to draw down troops and turn over security responsibility to Afghan forces by the end of 2014.

Efforts to reach a political solution to a conflict now more than a decade old will be on Clinton's agenda, along with support for Afghans as they step up their own security work.

Clinton will also discuss the future "strategic partnership" between Afghanistan and the United States after 2014, with an eye to eventually formalizing the alliance.

In her meetings with Karzai and other Afghan officials, Clinton is expected to preview plans for conferences on the future of Afghanistan due to be held in Istanbul in November and Bonn in December.

US officials hope the gatherings will tighten international cooperation on political and economic strategies to stabilize the country.

She is also expected to discuss Afghanistan's ties with neighboring Pakistan, accused by officials in both Kabul and the United States of working to undercut the US-led military campaign in order to protect its influence in the region.