В зависимости от контекста, может быть как страной-исполнителем программы, так и человеком, отделом или организацией.
Если country, как настаивает Галина, переводить в таких словосочетаниях как "страна", то станут нонсенсом такие словосочетания как: country representative, country office, country chapters, country networks, etc., как в примере ниже:

This project aims to build the institutional capacity of GEMSA chapters by appointing country implementers to assist in monitoring plans, to coordinate fundraising, assist with financial administration and ensure good governance through calling regular meetings and disseminating information and updating the website.
Background
During the last three years the GEMSA secretariat has focused on growing the network at a regional level and working with country representatives to establish country chapters. Currently, there are GEMSA chapters in 12 Southern African countries and members in Angola, the Democratic Republic of Congo and
Madagascar. The regional secretariat is well established with proper governance, financial and administrative systems in place. GEMSA has been working with country chapters to build the institutional capacity of in country networks. Much of GEMSA’s
work happens in country and it is crucial to support country chapters to develop their capacity to deliver effective programmes. To sustain the in country capacity building GEMSA is recommending that each chapter appoint a country implementer. http://www.gemsa.org.za/attachment_view.php?pa_id=258