Afghanistan needs a "stable security environment to prevent it from again becoming a safe haven for Al-Qaeda or other terrorists," a U.S. report says.
The report was released on January 11 by the Special Inspector General for Afghanistan Reconstruction (SIGAR), which gives independent oversight of U.S. reconstruction funds for the country.
It says Afghan security forces have "not yet been capable of securing all of Afghanistan and has lost territory to the insurgency."
Most NATO-led foreign combat forces pulled out of Afghanistan in 2014, leaving nearly 10,000 U.S. troops behind.
Afghan forces have since struggled to fend off the Taliban, which has gained control of more territory than any time since the U.S.-led invasion in 2001.
SIGAR described corruption as "one of the most serious threats to the U.S.-funded Afghanistan reconstruction effort."
"Powerful drug networks, mainly run by close-knit families and tribes, bankroll the insurgency and launder money," it also said.