In the wake of Tuesday's meeting between U.S. and Turkish government officials, the sources said that U-2 reconnaissance planes have been monitoring military movements along the two countries' borders, CNN reported.
Tensions in the region have grown since Turkey announced it would consider a military offensive on Iraqi soil if no action is taken against the Kurdistan Workers Party.
The Kurdish militant group, listed as a terrorist organization by the U.S. State Department, has been launching attacks against Turkish cites from inside Iraq's borders.
Pentagon spokesman Geoff Morrell said Wednesday that U.S. officials have been aiding Turkey, one of its fellow NATO members, by providing regional intelligence.
"We are assisting by supplying them, the Turks, with intelligence, lots of intelligence," Morrell said.
CNN said that while the United States is proving Turkey with intelligence, U.S. and Iraqi officials have openly opposed any cross-border hostilities by the Turkish military.