The United States is drastically increasing its support for Syrian opposition fighters and helping train rebels at a base in the region, the New York Times reported Thursday.Offering armed groups non-lethal assistance could help their military campaign, US administration officials told the New York Times. The training, which has reportedly already begun, represents the most extreme American involvement to date in the Syrian conflict, though the extent mission is not clear.According to the New York Times, Secretary of State John Kerry is expected to propose the idea of training rebel fighters at a meeting in Rome with Syrian opposition leaders, as part of his tour of Europe. Western and Arab officials will meet representatives of the Syrian opposition in Istanbul next Monday to discuss military and humanitarian support for rebels fighting President Bashar Assad, a European diplomatic source said on Thursday."The meeting aims to work directly with opposition structures to increase the level of support," the source said, adding that both civilian and military representatives of the Syrian opposition would attend.The source spoke on the margins of a meeting in Rome between the Syrian National Coalition - the main civilian opposition group - and Western and Arab nations.In a policy shift, the United States has decided to provide medical supplies and food to Syrian fighters, but will still oppose giving the rebels weapons, a source familiar with the matter said overnight. The White House press secretary said Wednesday that the US will increase aid to Syrians and the Syrian opposition in an effort to speed a political transition in Syria. Secretary of State John Kerry said earlier in the day that Syria's opposition needs more help in its struggle against Assad's regime, and that Washington wanted to find ways to speed up a political transition.