High Quality Content by WIKIPEDIA articles! The Office of National Assessments (ONA) is an Australian intelligence agency. ONA was established by the Office of National Assessments (ONA) Act 1977 as an independent body directly accountable to the Prime Minister of Australia. ONA provides all-source assessments on international political, strategic and economic developments to the Prime Minister and senior ministers in the National Security Committee of Cabinet. It also coordinates and evaluates the work and performance of Australia’s foreign intelligence agencies. ONA is not an intelligence collection agency.