WASHINGTON, July 2 (UPI) -- The United States is not involved in any relationship with the Kurdistan Workers' Party or its affiliates, a U.S. State Department spokesman said.

The Kurdistan Workers' Party, or PKK, and the Party for a Free Life in Kurdistan, or PJAK, are separatist groups operating in northern Iraq and neighboring regions in Iran and Turkey. An October piece in The New York Times (NYSE:NYT) described the PJAK as an offshoot of the PKK.

The PJAK has been known to launch attacks against Iranian forces from their areas of operation in the region. While the PKK is designated as a terrorist organization by the United States, the PJAK is not formally listed as such.

A report released in The New Yorker magazine by investigative journalist Seymour Hersh suggests U.S. covert operations agencies back the group, as well as the People's Mujahadin of Iran for their opposition to the Iranian regime.

In a news briefing with reporters, however, U.S. State Department deputy spokesman Tom Casey emphatically denied both the relationship between the PKK and the PJAK and U.S. affiliation with either group.