NATO Secretary-General Mark Rutte was upbeat that the military organization will agree on massive spending hikes at a “transformational summit” on Wednesday, as member state leaders including U.S. President Donald Trump assembled in the Netherlands.

NATO leaders agreed on Wednesday on a massive hike in defense spending after pressure from U.S. President Donald Trump, and expressed their “ironclad commitment” to come to each other’s aid if attacke

President Trump has long pushed the European allies to be more self-sufficient on defense, relying less on American protection. NATO committed to a major increase over the next decade.