Taliban and al Qaeda Remain Linked, U.N. Study Says

WASHINGTON—A United Nations report issued Monday found that Afghanistan’s Taliban has maintained close ties with al Qaeda, holding at least six high-level meetings with leaders of the group during more than a year of talks with the United States.

The U.N. findings point to the difficulty faced by the Taliban in implementing its side of the agreement signed with the U.S. in February. Under the terms, the U.S. will withdraw all its troops within 14 months in return for a Taliban guarantee that Afghanistan will never again become…