KYIV, Ukraine — Ukraine expects there will be around $3.5 billion by next month in a fund to buy weapons from the United States and help sustain its more than three-year fight against Russia’s all-out invasion, Ukrainian President Volodymyr Zelenskyy said Wednesday. The financial arrangement known as the Prioritized Ukraine Requirements List, or PURL, pools contributions from NATO members, except the United States, to purchase American weapons, munitions and equipment. “We received more than $2