The U.S. is beefing up joint intelligence efforts with Turkey to help that government better target terrorists in the region, according to U.S. officials, in an apparent bid to alleviate Turkish anxieties as the Pentagon implements a plan to arm Kurdish forces operating inside Syria.

The U.S. is increasing the capabilities of what is known as an “intelligence fusion center” in Ankara to help Turkish officials better identify and track the Kurdistan Workers’ Party, or PKK, a network that both the U.S. and Turkey have designated...