United States Vice President Joe Biden is on an unannounced visit to Afghanistan.
Mr Biden is there for talks with top officials including President Hamid Karzai.
White House Officials say that Mr Biden will assess progress in the key issue of handing over security from foreign to Afghan forces.
The United States aims to begin withdrawing its troops in July. But Republicans in the US Congress caution against abandoning a key ally.
Upon arriving at Kabul airport aboard Air Force Two, Mr Biden flew by helicopter to the US Embassy for talks with General David Petraeus and US Ambassador Karl Eikenberry.
The BBC reports the trip is Mr Biden's first time in Afghanistan as vice president. He was last in the country in January 2009.
