ISLAMABAD Chief of Army Staff, General Ashfaq Parvez Kayani, called on Prime Minister Syed Yousuf Raza Gilani at PMs House on Tuesday afternoon and discussed the overall security situation of the country. The COAS also apprised the Prime Minister of his forthcoming visit to China starting from 17th of this month. Sources informed that the Army Chief briefed the PM on Pak-US Defence Working Group, besides his recent meeting with General Stanley A McChrystal, Commander International Security Assistance Forces, Afghanistan. The overall situation in war on terror and its fallout on the tribal areas also came under the discussion.