WASHINGTON - Air Chief Marshal Sohail Aman, Chief of the Air Staff, Pakistan Air Force called on General Mark A. Welsh III, Chief of Staff USAF in his office at USAF Headquarters, Pentagon at Washington on Thursday. Both the dignitaries discussed matters of mutual interest. The Air Chief highlighted the contributions of Pakistan Armed Forces in the ongoing Operation Zarb-e-Azb and underscored the leading role being played by Pakistan Air Force.