ANKARA, Turkey (AP) — The United States says it has authorized rewards for information on the whereabouts of three top Kurdish rebel leaders wanted by Turkey, in a sign of improving ties between the NATO allies.

The announcement was made by U.S. Deputy Assistant Secretary of State Matthew Palmer, who was in Ankara on Tuesday.

Palmer said in a statement that the U.S. would pay up to $5 million for information leading to "the identification or location" of Murat Karayilan, up to $4 million for Cemal Bayik and $3 million for Duran Kalkan.

All three are senior leaders of the Kurdistan Workers' Party, or PKK, considered a terrorist organization by Turkey and the United States.

Last week, Turkey and the United States mutually removed sanctions imposed on each other's ministers.