By Marianna Parraga, Mayela Armas and Matt Spetalnick WASHINGTON/CARACAS (Reuters) – Top officials from the U.S. State and Treasury departments are discussing proposals for a fund that could release over $3 billion to provide humanitarian aid to Venezuelans through the United Nations, according to nine people close to the talks. The proposals offer a potential way to revive stalled political dialogue in Venezuela, and come as more Venezuelans try to reach the United States, creating clashes among U.S. politicians over immigration. Migrants arriving at the U.S.-Mexico border are prompting U.S. …