The Pentagon said on Tuesday it had not been contacted by WikiLeaks, despite claims that the whistle-blowing website sought its help reviewing thousands of classified Afghan war documents ahead of their release.U.S. officials have appealed to WikiLeaks not to post any additional documents and accused the group of endangering lives of Afghan contacts named in its initial release of tens of thousands of classified U.S. military reports last month. A WikiLeaks spokesman said on Tuesday he wanted the Defense Department's help reviewing 15,000 additional U.S. documents ahead of their potential release, according to The Daily Beast news website.Pentagon spokesman Col. Dave Lapan said WikiLeaks had not contacted the Defense Department.He declined to speculate on what might happen if they did request assistance.Admiral Mike Mullen, chairman of the U.S. military's Joint Chiefs of Staff, said last week that the group may be responsible for the deaths of U.S. troops and Afghan contacts exposed by the leak, one of the largest security breaches in U.S. military history."It is very harsh to hear that," Daniel Schmitt, a WikiLeaks spokesman in Germany, was quoted telling The Daily Beast. "We're not aware of any tragedies that have happened."