Say what you will though, the US has built up an impressive capacity to assist in humanitarian mission. Think back to aftermath of the Sumatra Earthquake and following Tsunami, the US Military was the one of the first on the scene and the only one with the capacity to coordinate a relief effort on that scale:
The United States has dispatched numerous C-5 Galaxy and C-17 Globemaster III strategic airlifters and ten C-130 Hercules tactical airlifters containing disaster supplies, nine P-3C Orion maritime patrol aircraft for search and rescue support, and several teams from the Departments of State and Defense to coordinate additional assistance. They are using Utapao Naval Air Base in Thailand as their regional hub. Additionally, the United States has offered assistance from its troops stationed in Japan. USS Abraham Lincoln aircraft carrier battle group, which was in port in Hong Kong, was dispatched to the coast of Sumatra to provide support to the Indonesian province of Aceh. In addition, an Expeditionary Strike Group led by USS Bonhomme Richard, scheduled for a port call in Guam, were dispatched to render assistance. A total of 48 Navy and Marine Corps helicopters are involved. Each ship can produce around 90,000 US gallons (340,000 L) of fresh water per day. The US Navy has also deployed the USNS Mercy, a 1,000-bed hospital ship (to be initially staffed to support 250 patient beds).[122] More than 12,600 Department of Defense personnel are involved in the relief effort, Operation Unified Assistance. USNS Mercy departed San Diego on 5 January 2005 en route to the tsunami-devastated regions of South East Asia, where she provided medical care to the victims of the disaster as part of Operation Unified Assistance, and further care as part of Theater Security Cooperation Program 2005. Combined, she provided 108,000 patient services, rendered by members of the Department of Defense, Project Hope, and the United States Public Health Service.
If you want real humanitarian assistance, you don't go running to the UN, you look to the US.