Chief of the Army Staff (COAS), General Ashfaq Parvez Kayani called on Prime Minister Yousaf Raza Gilani here at the Prime Minister House on Friday evening and discussed the PM Gilanis tour to USA.According to sources, PM and COAS also discussed matters relating to national security and the war on terror. A U.S. delegation led by Senator Max Sieben Baucus, Chairman of the Senate Committee of Finance and Senator Thomas Carper, Senate Homeland Security, Government Affairs and Finance Committee also called on COAS, the leaders discussed issues of mutual concern.