@Ana1234 - It is a bit awkward, but entirely necessary, because an NGO will often be welcome in places where a government sponsored agency would not be. Making it clear that an organization is not tied to a particular government can be vital in ensuring the safety of its workers and their ability to work unhindered, particularly in war-zones or on controversial subjects. This isn't just that they might be banned from a country if they are suspected spies or propagandists, it might also be that the country they were affiliated with would limit their ability to work.
An organisation might want to change the laws in the country they are working in, by providing better prison care, for example, but their country of origin might not want to rock the boat that way in public relations. So it's much safer for the NGO to declare upfront that they are not affiliated with any particular government and follow only their own code.