NATO has taken over the coordination of Western military aid to Ukraine from the United States, as planned, a source said on Tuesday, in a move widely seen as aiming to safeguard the support mechanism against NATO sceptic Donald Trump. The step, coming after a delay of several months, gives NATO a more direct role in the war against Russia's invasion while stopping well short of committing its own forces. Diplomats, however, acknowledge that the handover to NATO may have a limited effect given that the U.S. under Trump could still deal a major setback to Ukraine by slashing its support as it is the alliance's dominant power and provides the majority of arms to Kyiv. Trump, who will take office in January, has said wants to end the war in Ukraine swiftly but not how he aims to do so. He has long criticized the scale of U.S. financial and military aid to Ukraine.