"The Obama administration remains fully committed to combating threats of terrorism in Afghanistan," she said.
Napolitano's New Year's visit to Afghanistan is focused on efforts to shore up security along the Afghanistan-Pakistan border to disrupt the movement of terrorists and goods that support terrorist operations, the Defense Department said in a release Sunday.
While in the Afghan capital, Napolitano toured security operations at Afghanistan's Torkham Border Crossing, discussing the Department of Homeland Security efforts to help the Afghan government boost customs and border control.
"Building and maintaining a strong border crossing system is critical to the stability and security of Afghanistan," she said. "Over the past year, the Department of Homeland Security has worked closely with the Afghan government to help establish a border security and customs system to counter terrorism while facilitating legitimate travel and trade."
The department also is assisting its Afghan counterparts in staunching the flow of chemicals used to manufacture bombs, and in establishing an Afghan customs academy, the Pentagon reported.
From Afghanistan, Napolitano was to travel to Qatar Monday to discuss efforts to secure global aviation and supply chain systems against threats of terrorism and international crime, officials said.