Hillary Clinton in Afghanistan ahead of donor meeting

US Secretary of State Hillary Clinton has arrived in Afghanistan on an unannounced visit.

Mrs Clinton is to meet President Hamid Karzai, one day ahead of a major conference of Afghanistan's foreign donors in Japan.

The gathering in Tokyo is expected to discuss how to support Kabul after most of the 130,000 Nato-led troops leave Afghanistan at the end of 2014.

Taliban and other insurgents have stepped up attacks in recent months.

A senior state department official told reporters the visit to Kabul would be a brief stop during Mrs Clinton's journey to Tokyo.

"The secretary wanted to be able stop in Kabul en route to Tokyo, in large part just to check signals before this last major, significant ministerial conference," the official said.

Participants at Sunday's meeting in Japan are expected to commit almost $4bn in annual development aid to Afghanistan.