Biden's visit comes barely a month after /*President Barack Obama*/ traveled to Afghanistan.
The president told /*U.S.*/ troops they were making progress in their mission to fight terrorism.
Biden is scheduled to meet with Afghan president Hamid Karzai. Karzai's government is plagued by charges of corruption and U.S. officials have expressed grave concerns about how this is affecting efforts to rebuild the country.
The White House is pushing what it calls a "transition to Afghan-led security" beginning this year.
The U.S. is to begin withdrawing combat forces from Afghanistan in July, and questions remain about the ability of the country's security forces to take up the fight in the face of a virulent insurgency.
/*NATO*/ hopes Afghan forces will assume full responsibility for security by 2014.
The Associated Press contributed to this report.
