Utter nonsense. This is patently untrue. There is no such registration process in the US. NGOs in the US who file for not-for-profit status under section 501c3 of the IRS tax code are free to accept donations from charitable sources abroad - including governmental sources - and to express political opinions that include direct opposition to governmental positions.
Germany warns of possible attacks on public transport in Istanbul (Reuters)
from the article: Knesset revives attempt to restrict foreign funding of left-wing NGOs